draw beam wider at the source than at the target

CMakeLists.txt

@@ -4,10 +4,20 @@ message(STATUS "Using CMake ${CMAKE_VERSION}")
 
 include(cmake/add_files.cmake)
 include(cmake/create_source_groups.cmake)
+include(cmake/version.cmake)
 
 # Project ----------------------------------------------------------------------
 
-project(DotaFactory)
+# Product identity — anything that depends on the product/project name is defined
+# here so it lives in a single place and can change in the future. These values
+# feed the build targets in src/CMakeLists.txt and the Windows version resource
+# (see cmake/version.rc.in).
+set(PRODUCT_NAME "DotaFactory")            # internal name and executable base name
+set(PRODUCT_DISPLAY_NAME "Dota Factory")   # human-readable product / file description
+set(PRODUCT_COMPANY "TODO: company")       # placeholder
+set(PRODUCT_COPYRIGHT "TODO: copyright")   # placeholder
+
+project(${PRODUCT_NAME})
 
 set(CMAKE_BUILD_TYPE_INIT "Release")
 

bin/app/data/config/buildings.toml

@@ -1,5 +1,6 @@
 [[building]]
 id = "belt"
+tooltip = "Transports items one tile at a time in the direction it faces."
 cost = 2
 player_placeable = true
 construction_time_seconds = 0.2
@@ -7,6 +8,7 @@ surface_mask = ["A>"]
 
 [[building]]
 id = "splitter"
+tooltip = "Splits an incoming item stream between two outputs, with optional per-output filters."
 cost = 3
 player_placeable = true
 construction_time_seconds = 0.5
@@ -14,6 +16,7 @@ surface_mask = ["<A>"]
 
 [[building]]
 id = "tunnel_entry"
+tooltip = "Sends items underground to a matching tunnel exit, letting belts cross."
 cost = 5
 player_placeable = true
 construction_time_seconds = 0.5
@@ -21,6 +24,7 @@ surface_mask = ["A>"]
 
 [[building]]
 id = "tunnel_exit"
+tooltip = "Receives items from a matching tunnel entry and pushes them onward."
 cost = 5
 player_placeable = true
 construction_time_seconds = 0.5
@@ -28,6 +32,7 @@ surface_mask = ["A>"]
 
 [[building]]
 id = "miner"
+tooltip = "Extracts a selected ore from the asteroid; every tile yields any ore."
 cost = 15
 player_placeable = true
 construction_time_seconds = 1
@@ -37,6 +42,7 @@ surface_mask = [
 
 [[building]]
 id = "smelter"
+tooltip = "Melts ore or scrap into basic materials. No recipe selection needed."
 cost = 20
 player_placeable = true
 construction_time_seconds = 1
@@ -47,6 +53,7 @@ surface_mask = [
 
 [[building]]
 id = "assembler"
+tooltip = "Crafts a selected recipe from the production tree into intermediate or final parts."
 cost = 35
 player_placeable = true
 construction_time_seconds = 1
@@ -57,6 +64,7 @@ surface_mask = [
 
 [[building]]
 id = "reprocessing_plant"
+tooltip = "Consumes scrap and yields one random higher-tier product per cycle."
 cost = 40
 player_placeable = true
 construction_time_seconds = 1
@@ -68,6 +76,7 @@ surface_mask = [
 
 [[building]]
 id = "shipyard"
+tooltip = "Builds autonomous combat ships from a selected schematic and module layout."
 cost = 60
 player_placeable = true
 construction_time_seconds = 1
@@ -78,10 +87,12 @@ surface_mask = [
 
 [[building]]
 id = "salvage_bay"
+tooltip = "Drop-off point where salvage ships unload collected scrap onto belts."
 cost = 25
 player_placeable = true
 construction_time_seconds = 1
+output_buffer_capacity = 20
 surface_mask = [
-  "SAA",
-  "SAA>",
+  "<AAS",
+  " AAS",
 ]

bin/app/data/config/modules.toml

@@ -1,21 +1,29 @@
 # modules.toml
 #
-# First real-content iteration: module ids and surface masks are the designed
-# content; stats, materials, and threat costs are placeholders until the
-# recipe and balancing passes.
+# Production tree v2: all weapons are railguns for now — the implementation
+# (instant damage, no projectile, no ammunition) stays as-is and the beam
+# visual reads as a tracer round. Lasers are reserved for a future distinct
+# weapon type (see docs/content_design.md, "Production tree v2 — Weapons").
+# Combat stats are placeholders until the arena balancing pass;
+# production_time_seconds values come from the numbers pass.
+#
+# Unlock progression is mostly disabled (unlock_at_station_level = -1) pending
+# the pacing pass. The railguns are the exception: railgun_m is gated to
+# station level 1, and railgun_l requires railgun_m to be unlocked first
+# (unlock_requires) — a demonstration of the prerequisite chain.
 #
 # Surface mask footprint ladder — footprints gate which hulls can mount a
 # module, purely through geometry (see ships.toml for the matching hull
 # grids):
 #
-#   1x1       laser_cannon_s, salvager, repair_tool   fits every hull, incl. drones
+#   1x1       railgun_s, salvager, repair_tool        fits every hull, incl. drones
 #   1x2       maneuvering_thrusters, sensor_booster,
 #             armor_plates                            frigate and up
 #   1x3       afterburner                             frigate and up (eats most of a frigate)
 #   L-shape   weapon_stabilizer, weapon_primer,
 #             weapon_upgrade                          frigate and up
-#   2x2       laser_cannon_m, drone_bay               cruiser and up (no 2x2 area on s hulls)
-#   3x3       laser_cannon_l                          battleship and up (no 3x3 area on m hulls)
+#   2x2       railgun_m, drone_bay                    cruiser and up (no 2x2 area on s hulls)
+#   3x3       railgun_l                               battleship and up (no 3x3 area on m hulls)
 #   2x6       drone_hangar                            carrier only
 
 # -----------------------------------------------------------------------------
@@ -23,13 +31,14 @@
 # -----------------------------------------------------------------------------
 
 [[module]]
-id = "laser_cannon_s"
+id = "railgun_s"
+tooltip = "Small railgun. Fast-firing, short range, low damage; fits any hull."
 unlock_at_station_level = -1
 surface_mask = ["O"]
-materials = [{item = "laser_cannon_s_module", amount = 1}]
-production_time_seconds = 0.5
+materials = [{item = "railgun_s_module", amount = 1}]
+production_time_seconds = 1
 fill_color = "#FF8040"
-glyph = "Ls"
+glyph = "Rs"
 
 [module.weapon]
 damage = 2
@@ -38,36 +47,39 @@ attack_rate_hz = 2.0
 
 
 [[module]]
-id = "laser_cannon_m"
-unlock_at_station_level = -1
+id = "railgun_m"
+tooltip = "Medium railgun. Higher damage at longer range; needs a 2x2 slot."
+unlock_at_station_level = 2
 surface_mask = [
     "OO",
     "OO"]
-materials = [{item = "laser_cannon_m_module", amount = 1}]
-production_time_seconds = 2
+materials = [{item = "railgun_m_module", amount = 1}]
+production_time_seconds = 3
 fill_color = "#FF8040"
-glyph = "Lm"
+glyph = "Rm"
 
 [module.weapon]
-damage = 10
+damage = 14
 attack_range_m = 70
 attack_rate_hz = 1.5
 
 
 [[module]]
-id = "laser_cannon_l"
-unlock_at_station_level = -1
+id = "railgun_l"
+tooltip = "Large railgun. Heavy damage at long range; needs a 3x3 slot."
+unlock_at_station_level = 6
+unlock_requires = ["railgun_m"]
 surface_mask = [
     "OOO",
     "OOO",
     "OOO"]
-materials = [{item = "laser_cannon_l_module", amount = 1}]
-production_time_seconds = 8
+materials = [{item = "railgun_l_module", amount = 1}]
+production_time_seconds = 4
 fill_color = "#FF8040"
-glyph = "Ll"
+glyph = "Rl"
 
 [module.weapon]
-damage = 40
+damage = 52
 attack_range_m = 100
 attack_rate_hz = 0.8
 
@@ -77,31 +89,33 @@ attack_rate_hz = 0.8
 
 [[module]]
 id = "salvager"
+tooltip = "Collects scrap from wrecks and stores it in the ship's cargo hold."
 unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "salvager_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#AACC44"
 glyph = "Sv"
 
 [module.salvage]
-collection_range_m = 500
-cargo_capacity = 10
+collection_range_m = 60
+cargo_capacity = 20
 collection_rate_hz = 0.5
 
 
 [[module]]
 id = "repair_tool"
-unlock_at_station_level = -1
+tooltip = "Repairs damaged friendly ships and defence stations within range."
+unlock_at_station_level = 0
 surface_mask = ["O"]
 materials = [{item = "repair_tool_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#66CCFF"
 glyph = "Rp"
 
 [module.repair]
 repair_rate_hz = 1
-repair_amount_hp = 6
+repair_amount_hp = 4
 repair_range_m = 80
 
 # -----------------------------------------------------------------------------
@@ -110,10 +124,11 @@ repair_range_m = 80
 
 [[module]]
 id = "afterburner"
-unlock_at_station_level = -1
+tooltip = "Greatly boosts top speed and forward acceleration."
+unlock_at_station_level = 2
 surface_mask = ["OOO"]
 materials = [{item = "afterburner_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "Ab"
 
@@ -124,10 +139,11 @@ added_main_acceleration_mpss = 60
 
 [[module]]
 id = "maneuvering_thrusters"
-unlock_at_station_level = -1
+tooltip = "Improves top speed and lateral/braking acceleration."
+unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "maneuvering_thrusters_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "Mt"
 
@@ -141,23 +157,25 @@ added_maneuvering_acceleration_mpss = 10
 
 [[module]]
 id = "armor_plates"
-unlock_at_station_level = -1
+tooltip = "Adds a large flat bonus to the ship's hit points."
+unlock_at_station_level = 0
 surface_mask = ["OO"]
 materials = [{item = "armor_plates_module", amount = 1}]
-production_time_seconds = 3
+production_time_seconds = 1
 fill_color = "#808080"
 glyph = "A"
 
 [module.health]
-added_hp = 40
+added_hp = 1200
 
 
 [[module]]
 id = "sensor_booster"
-unlock_at_station_level = -1
+tooltip = "Extends the ship's sensor range."
+unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "sensor_booster_module", amount = 1}]
-production_time_seconds = 2
+production_time_seconds = 1
 fill_color = "#40A0FF"
 glyph = "S"
 
@@ -170,13 +188,14 @@ added_sensor_range_m = 50
 
 [[module]]
 id = "weapon_upgrade"
-unlock_at_station_level = -1
+tooltip = "Increases the damage of all weapons on the ship."
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_upgrade_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 2
 fill_color = "#FF4040"
 glyph = "Wu"
 
@@ -186,13 +205,14 @@ multiplied_damage = 1.2
 
 [[module]]
 id = "weapon_primer"
-unlock_at_station_level = -1
+tooltip = "Increases the fire rate of all weapons on the ship."
+unlock_at_station_level = 4
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_primer_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 2
 fill_color = "#FF4040"
 glyph = "Wp"
 
@@ -202,18 +222,19 @@ multiplied_attack_rate_hz = 1.2
 
 [[module]]
 id = "weapon_stabilizer"
-unlock_at_station_level = -1
+tooltip = "Extends weapon range at the cost of some fire rate."
+unlock_at_station_level = 3
 surface_mask = [
     "OO",
     "OX",
 ]
 materials = [{item = "weapon_stabilizer_module", amount = 1}]
-production_time_seconds = 4
+production_time_seconds = 1
 fill_color = "#FF4040"
 glyph = "Ws"
 
 [module.weapon]
-multiplied_attack_range_m = 1.5
+multiplied_attack_range_m = 1.3
 multiplied_attack_rate_hz = 0.8
 
 # -----------------------------------------------------------------------------
@@ -225,23 +246,25 @@ multiplied_attack_rate_hz = 0.8
 
 [[module]]
 id = "drone_bay"
-unlock_at_station_level = -1
+tooltip = "Drone launch bay (capability not yet implemented)."
+unlock_at_station_level = 5
 surface_mask = [
     "OO",
     "OO"]
 materials = [{item = "drone_bay_module", amount = 1}]
-production_time_seconds = 5
+production_time_seconds = 3
 fill_color = "#CC66FF"
 glyph = "Db"
 
 
 [[module]]
 id = "drone_hangar"
-unlock_at_station_level = -1
+tooltip = "Large drone hangar (capability not yet implemented)."
+unlock_at_station_level = 9
 surface_mask = [
     "OOOOOO",
     "OOOOOO"]
 materials = [{item = "drone_hangar_module", amount = 1}]
-production_time_seconds = 20
+production_time_seconds = 6
 fill_color = "#9933CC"
 glyph = "Dh"

bin/app/data/config/recipes.toml

@@ -1,24 +1,26 @@
 # recipes.toml
 #
-# First real-content iteration of the production tree. Quantities and
-# durations are a first guess; the balancing pass will tune them and assign
-# real unlock_at_station_level values (everything is unlocked for now so the
-# full tree is testable).
+# Production tree v2 (structure in docs/content_design.md, numbers with
+# derivations in docs/balancing/derived.md). Quantities and durations are tuned so that every
+# fitted ship lands on the threat-cost ladder and the ratio curve is
+# realized: tier 1 ratios are 1:1, tier 2 ratios are 2:3, tier 3+ ratios
+# are deliberately strange.
 #
-# Input chain per game phase — each phase adds exactly one new base input:
+# Input chain per game phase — each phase transition adds exactly one new
+# base input:
 #
-#   early  iron_ore + copper_ore   -> ingots -> copper_wire, steel_plate,
-#                                    circuit_board
-#   mid    + titanium_ore          -> titanium_frame; assembler-made
-#                                    mechanical_parts, targeting_unit,
-#                                    drive_unit
-#   late   + advanced_alloy        -> reinforced_plating, capital_core.
-#                                    advanced_alloy CANNOT be mined; it only
-#                                    comes from reprocessing salvaged scrap,
-#                                    so capital production requires combat.
+#   early  iron_ore + copper_ore    minable on every asteroid tile (the
+#                                   asteroid is an M-type body — its bulk
+#                                   rock IS ore)
+#   mid    + quartz                 geode deposits in expansion territory
+#                                   (deposit gating pending — see action
+#                                   item 5 in docs/balancing/README.md;
+#                                   until then quartz mines anywhere)
+#   late   + voidsteel              battle-forged: ONLY from reprocessing
+#                                   salvaged scrap, so capital production
+#                                   requires combat
 #
-# Run tools/verify_recipes.py after editing to check that every consumed
-# item has a producer and every item has a visuals.toml entry.
+# Run tools/verify_recipes.py and tools/threat_report.py after editing.
 
 # -----------------------------------------------------------------------------
 # Mining (tier 0)
@@ -36,404 +38,409 @@ id = "mine_copper_ore"
 building = "miner"
 inputs = []
 outputs = [{item = "copper_ore", amount = 1}]
-duration_seconds = 1.5
+duration_seconds = 1.0
 
-# Titanium is the midgame ore: mined three times slower than iron.
 [[recipe]]
-id = "mine_titanium_ore"
+id = "mine_quartz"
 building = "miner"
 inputs = []
-outputs = [{item = "titanium_ore", amount = 1}]
-duration_seconds = 3.0
+outputs = [{item = "quartz", amount = 1}]
+duration_seconds = 2.0
 
 # -----------------------------------------------------------------------------
-# Smelting (tier 1)
+# Smelting (tier 1) — one recipe per input item; ratios are 1:1 with miners.
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "iron_ingot"
 building = "smelter"
-inputs = [{item = "iron_ore", amount = 2}]
+inputs = [{item = "iron_ore", amount = 1}]
 outputs = [{item = "iron_ingot", amount = 1}]
-duration_seconds = 2.0
+duration_seconds = 1.0
 
 [[recipe]]
 id = "copper_ingot"
 building = "smelter"
-inputs = [{item = "copper_ore", amount = 2}]
+inputs = [{item = "copper_ore", amount = 1}]
 outputs = [{item = "copper_ingot", amount = 1}]
-duration_seconds = 2.5
+duration_seconds = 1.0
 
 [[recipe]]
-id = "titanium_ingot"
+id = "silicon"
 building = "smelter"
-inputs = [{item = "titanium_ore", amount = 3}]
-outputs = [{item = "titanium_ingot", amount = 1}]
-duration_seconds = 4.0
+inputs = [{item = "quartz", amount = 1}]
+outputs = [{item = "silicon", amount = 1}]
+duration_seconds = 2.0
+
+# Scrap smelting: the safe, boring sink. Deliberately value-losing (4 threat
+# of scrap becomes a 2-threat ingot) — reprocessing is the value-preserving
+# path.
+[[recipe]]
+id = "scrap_smelting"
+building = "smelter"
+inputs = [{item = "scrap", amount = 1}]
+outputs = [{item = "iron_ingot", amount = 1}]
+duration_seconds = 1.0
 
 # -----------------------------------------------------------------------------
-# Reprocessing
-#
-# The only source of advanced_alloy: salvaged scrap from destroyed ships.
+# Reprocessing — the only source of voidsteel (battle-forged; formed when
+# weapon plasma anneals hull metal in the violence of ship destruction).
+# Weights are authored for the fully unlocked pool state; the pool
+# renormalizes over implicitly unlocked items early game.
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "reprocessing_cycle"
 building = "reprocessing_plant"
-inputs = [{item = "scrap", amount = 5}]
-duration_seconds = 3.0
+inputs = [{item = "scrap", amount = 4}]
+duration_seconds = 4.0
 
   [[recipe.outputs]]
   item = "iron_ingot"
-  amount = 2
-  probability = 0.45
+  amount = 1
+  probability = 0.3
 
   [[recipe.outputs]]
   item = "copper_ingot"
   amount = 1
-  probability = 0.25
+  probability = 0.3
 
   [[recipe.outputs]]
-  item = "titanium_ingot"
+  item = "silicon"
   amount = 1
-  probability = 0.15
+  probability = 0.2
 
   [[recipe.outputs]]
-  item = "advanced_alloy"
+  item = "voidsteel"
   amount = 1
-  probability = 0.15
+  probability = 0.2
 
 # -----------------------------------------------------------------------------
-# Basic components (tier 2, early game)
+# Tier 2 — early intermediates (clean ratios, ~2:3)
 # -----------------------------------------------------------------------------
 
-[[recipe]]
-id = "copper_wire"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "copper_ingot", amount = 1}]
-outputs = [{item = "copper_wire", amount = 2}]
-duration_seconds = 1.5
-
 [[recipe]]
 id = "steel_plate"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [{item = "iron_ingot", amount = 2}]
 outputs = [{item = "steel_plate", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "copper_wire"
+building = "assembler"
+inputs = [{item = "copper_ingot", amount = 1}]
+outputs = [{item = "copper_wire", amount = 2}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "copper_coil"
+building = "assembler"
+inputs = [{item = "copper_wire", amount = 2}]
+outputs = [{item = "copper_coil", amount = 1}]
+duration_seconds = 1.5
+
+# Depth-3 chain (ore -> ingot -> plate -> block) is the factory's
+# doubling-time knob; see the block economy rules in docs/balancing/rules.md.
+# Explicitly unlocked at start (-1): building blocks appear in no
+# schematic's materials, so implicit unlocking can never reach this recipe.
+[[recipe]]
+id = "building_block"
+unlock_at_station_level = -1
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 2}]
+outputs = [{item = "building_block", amount = 4}]
+duration_seconds = 2.0
+
+# -----------------------------------------------------------------------------
+# Tier 3 — mid intermediates (strange ratios begin; need quartz)
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "control_chip"
+building = "assembler"
+inputs = [{item = "silicon", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "control_chip", amount = 1}]
+duration_seconds = 5.0
+
+[[recipe]]
+id = "capacitor_bank"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 2}, {item = "silicon", amount = 1}]
+outputs = [{item = "capacitor_bank", amount = 1}]
+duration_seconds = 5.0
+
+# The quality gate for m+ hulls: a deliberately long-running recipe
+# (time-heavy archetype).
+[[recipe]]
+id = "hardened_steel"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 3}]
+outputs = [{item = "hardened_steel", amount = 1}]
+duration_seconds = 12.0
+
+[[recipe]]
+id = "ceramic_plate"
+building = "assembler"
+inputs = [{item = "quartz", amount = 2}]
+outputs = [{item = "ceramic_plate", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "drive_unit"
+building = "assembler"
+inputs = [
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 2},
+    {item = "control_chip", amount = 1},
+]
+outputs = [{item = "drive_unit", amount = 1}]
+duration_seconds = 8.0
+
+# -----------------------------------------------------------------------------
+# Tier 4 — late intermediates (need voidsteel)
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "voidsteel_plate"
+building = "assembler"
+inputs = [{item = "voidsteel", amount = 1}, {item = "hardened_steel", amount = 1}]
+outputs = [{item = "voidsteel_plate", amount = 1}]
+duration_seconds = 8.0
+
+[[recipe]]
+id = "capital_core"
+building = "assembler"
+inputs = [
+    {item = "voidsteel", amount = 2},
+    {item = "capacitor_bank", amount = 1},
+    {item = "control_chip", amount = 1},
+]
+outputs = [{item = "capital_core", amount = 1}]
+duration_seconds = 10.0
+
+# -----------------------------------------------------------------------------
+# Shortcut recipes — drop-only assembler recipe schematics
+# (unlock_at_station_level >= 0). Pure rewards: item threat stays defined by
+# the base (expensive) path via the max rule, so shortcuts give real factory
+# efficiency without shifting any balance.
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "shortcut_steel_plate"
+unlock_at_station_level = 1
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 3}]
+outputs = [{item = "steel_plate", amount = 1}]
 duration_seconds = 2.0
 
 [[recipe]]
-id = "circuit_board"
-unlock_at_station_level = -1
+id = "shortcut_control_chip"
+unlock_at_station_level = 2
 building = "assembler"
-inputs = [{item = "iron_ingot", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "circuit_board", amount = 1}]
-duration_seconds = 2.0
+inputs = [{item = "quartz", amount = 2}]
+outputs = [{item = "control_chip", amount = 1}]
+duration_seconds = 4.0
 
 [[recipe]]
-id = "building_blocks"
-unlock_at_station_level = -1
+id = "shortcut_hardened_steel"
+unlock_at_station_level = 2
 building = "assembler"
 inputs = [{item = "iron_ingot", amount = 4}]
-outputs = [{item = "building_block", amount = 10}]
-duration_seconds = 4.0
-
-# -----------------------------------------------------------------------------
-# Advanced components (tier 3, midgame)
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "mechanical_parts"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 1}, {item = "iron_ingot", amount = 1}]
-outputs = [{item = "mechanical_parts", amount = 2}]
-duration_seconds = 2.5
-
-[[recipe]]
-id = "targeting_unit"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 2}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "targeting_unit", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "drive_unit"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 1},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
-outputs = [{item = "drive_unit", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "titanium_frame"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "titanium_ingot", amount = 2}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "titanium_frame", amount = 1}]
-duration_seconds = 4.0
-
-# -----------------------------------------------------------------------------
-# Capital components (tier 4, lategame — gated on advanced_alloy)
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "reinforced_plating"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 2}, {item = "advanced_alloy", amount = 1}]
-outputs = [{item = "reinforced_plating", amount = 1}]
-duration_seconds = 5.0
-
-[[recipe]]
-id = "capital_core"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "targeting_unit", amount = 1},
-    {item = "drive_unit", amount = 1},
-    {item = "advanced_alloy", amount = 2},
-]
-outputs = [{item = "capital_core", amount = 1}]
+outputs = [{item = "hardened_steel", amount = 1}]
 duration_seconds = 8.0
 
-# -----------------------------------------------------------------------------
-# Module items — early game
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "laser_cannon_s_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "iron_ingot", amount = 2}, {item = "circuit_board", amount = 1}]
-outputs = [{item = "laser_cannon_s_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "salvager_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 1}, {item = "circuit_board", amount = 1}]
-outputs = [{item = "salvager_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "repair_tool_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 2}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "repair_tool_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "armor_plates_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "steel_plate", amount = 2}]
-outputs = [{item = "armor_plates_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "sensor_booster_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "circuit_board", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "sensor_booster_module", amount = 1}]
-duration_seconds = 3.0
-
-[[recipe]]
-id = "maneuvering_thrusters_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "mechanical_parts", amount = 1}, {item = "copper_wire", amount = 1}]
-outputs = [{item = "maneuvering_thrusters_module", amount = 1}]
-duration_seconds = 3.0
-
-# -----------------------------------------------------------------------------
-# Module items — midgame
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "afterburner_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "drive_unit", amount = 1}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "afterburner_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_upgrade_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "steel_plate", amount = 1}]
-outputs = [{item = "weapon_upgrade_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_primer_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "copper_wire", amount = 2}]
-outputs = [{item = "weapon_primer_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "weapon_stabilizer_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "mechanical_parts", amount = 1}]
-outputs = [{item = "weapon_stabilizer_module", amount = 1}]
-duration_seconds = 4.0
-
-[[recipe]]
-id = "laser_cannon_m_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [{item = "targeting_unit", amount = 1}, {item = "titanium_frame", amount = 1}]
-outputs = [{item = "laser_cannon_m_module", amount = 1}]
-duration_seconds = 6.0
-
-[[recipe]]
-id = "drone_bay_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "titanium_frame", amount = 1},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
-outputs = [{item = "drone_bay_module", amount = 1}]
-duration_seconds = 6.0
-
-# -----------------------------------------------------------------------------
-# Module items — lategame
-# -----------------------------------------------------------------------------
-
-[[recipe]]
-id = "laser_cannon_l_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "targeting_unit", amount = 2},
-    {item = "reinforced_plating", amount = 2},
-    {item = "titanium_frame", amount = 1},
-]
-outputs = [{item = "laser_cannon_l_module", amount = 1}]
-duration_seconds = 12.0
-
-[[recipe]]
-id = "drone_hangar_module"
-unlock_at_station_level = -1
-building = "assembler"
-inputs = [
-    {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 2},
-    {item = "reinforced_plating", amount = 2},
-]
-outputs = [{item = "drone_hangar_module", amount = 1}]
-duration_seconds = 20.0
-
 # -----------------------------------------------------------------------------
 # Ship hulls
 # -----------------------------------------------------------------------------
 
 [[recipe]]
 id = "drone_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [{item = "iron_ingot", amount = 5}, {item = "circuit_board", amount = 1}]
+inputs = [{item = "iron_ingot", amount = 1}]
 outputs = [{item = "drone_hull", amount = 1}]
-duration_seconds = 4.0
+duration_seconds = 1.0
 
 [[recipe]]
 id = "frigate_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 3},
-    {item = "mechanical_parts", amount = 1},
-    {item = "circuit_board", amount = 1},
-]
+inputs = [{item = "steel_plate", amount = 2}, {item = "copper_wire", amount = 1}]
 outputs = [{item = "frigate_hull", amount = 1}]
-duration_seconds = 8.0
+duration_seconds = 2.0
 
 [[recipe]]
 id = "destroyer_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "steel_plate", amount = 5},
-    {item = "mechanical_parts", amount = 2},
-    {item = "circuit_board", amount = 1},
-]
+inputs = [{item = "steel_plate", amount = 3}, {item = "copper_coil", amount = 2}]
 outputs = [{item = "destroyer_hull", amount = 1}]
-duration_seconds = 10.0
+duration_seconds = 4.0
 
 [[recipe]]
 id = "cruiser_hull"
-unlock_at_station_level = -1
 building = "assembler"
-inputs = [
-    {item = "titanium_frame", amount = 2},
-    {item = "steel_plate", amount = 4},
-    {item = "drive_unit", amount = 1},
-]
+inputs = [{item = "hardened_steel", amount = 2}, {item = "control_chip", amount = 2}]
 outputs = [{item = "cruiser_hull", amount = 1}]
-duration_seconds = 15.0
+duration_seconds = 6.0
 
 [[recipe]]
 id = "battlecruiser_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
-    {item = "titanium_frame", amount = 3},
-    {item = "steel_plate", amount = 6},
+    {item = "hardened_steel", amount = 3},
+    {item = "control_chip", amount = 2},
     {item = "drive_unit", amount = 1},
-    {item = "targeting_unit", amount = 1},
 ]
 outputs = [{item = "battlecruiser_hull", amount = 1}]
-duration_seconds = 20.0
+duration_seconds = 8.0
 
 [[recipe]]
 id = "battleship_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
-    {item = "titanium_frame", amount = 4},
-    {item = "reinforced_plating", amount = 2},
-    {item = "drive_unit", amount = 2},
+    {item = "voidsteel_plate", amount = 3},
+    {item = "drive_unit", amount = 1},
+    {item = "control_chip", amount = 2},
 ]
 outputs = [{item = "battleship_hull", amount = 1}]
-duration_seconds = 30.0
+duration_seconds = 10.0
 
 [[recipe]]
 id = "dreadnought_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
+    {item = "voidsteel_plate", amount = 5},
     {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 6},
-    {item = "reinforced_plating", amount = 4},
     {item = "drive_unit", amount = 2},
 ]
 outputs = [{item = "dreadnought_hull", amount = 1}]
-duration_seconds = 60.0
+duration_seconds = 12.0
 
 [[recipe]]
 id = "carrier_hull"
-unlock_at_station_level = -1
 building = "assembler"
 inputs = [
+    {item = "voidsteel_plate", amount = 5},
     {item = "capital_core", amount = 1},
-    {item = "titanium_frame", amount = 5},
-    {item = "reinforced_plating", amount = 3},
     {item = "drive_unit", amount = 2},
 ]
 outputs = [{item = "carrier_hull", amount = 1}]
-duration_seconds = 60.0
+duration_seconds = 12.0
+
+# -----------------------------------------------------------------------------
+# Module prefabs
+# -----------------------------------------------------------------------------
+
+[[recipe]]
+id = "railgun_s_module"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 1}]
+outputs = [{item = "railgun_s_module", amount = 1}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "salvager_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "salvager_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "repair_tool_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_wire", amount = 2}]
+outputs = [{item = "repair_tool_module", amount = 1}]
+duration_seconds = 2.0
+
+# Material-heavy, fast: the armor archetype.
+[[recipe]]
+id = "armor_plates_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 4}]
+outputs = [{item = "armor_plates_module", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "maneuvering_thrusters_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "maneuvering_thrusters_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "sensor_booster_module"
+building = "assembler"
+inputs = [{item = "copper_wire", amount = 2}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "sensor_booster_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "afterburner_module"
+building = "assembler"
+inputs = [{item = "copper_coil", amount = 2}, {item = "steel_plate", amount = 1}]
+outputs = [{item = "afterburner_module", amount = 1}]
+duration_seconds = 3.0
+
+[[recipe]]
+id = "weapon_stabilizer_module"
+building = "assembler"
+inputs = [{item = "steel_plate", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_stabilizer_module", amount = 1}]
+duration_seconds = 2.0
+
+[[recipe]]
+id = "weapon_primer_module"
+building = "assembler"
+inputs = [{item = "capacitor_bank", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_primer_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "weapon_upgrade_module"
+building = "assembler"
+inputs = [{item = "control_chip", amount = 1}, {item = "copper_coil", amount = 1}]
+outputs = [{item = "weapon_upgrade_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "railgun_m_module"
+building = "assembler"
+inputs = [
+    {item = "capacitor_bank", amount = 1},
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 1},
+]
+outputs = [{item = "railgun_m_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "drone_bay_module"
+building = "assembler"
+inputs = [
+    {item = "control_chip", amount = 1},
+    {item = "steel_plate", amount = 2},
+    {item = "copper_coil", amount = 1},
+]
+outputs = [{item = "drone_bay_module", amount = 1}]
+duration_seconds = 4.0
+
+[[recipe]]
+id = "railgun_l_module"
+building = "assembler"
+inputs = [
+    {item = "capacitor_bank", amount = 1},
+    {item = "hardened_steel", amount = 2},
+    {item = "ceramic_plate", amount = 1},
+]
+outputs = [{item = "railgun_l_module", amount = 1}]
+duration_seconds = 6.0
+
+[[recipe]]
+id = "drone_hangar_module"
+building = "assembler"
+inputs = [
+    {item = "voidsteel_plate", amount = 1},
+    {item = "control_chip", amount = 2},
+    {item = "drive_unit", amount = 1},
+]
+outputs = [{item = "drone_hangar_module", amount = 1}]
+duration_seconds = 10.0

bin/app/data/config/ships.toml

@@ -4,6 +4,11 @@
 # content; stats, materials, and production times are placeholders until the
 # recipe and balancing passes.
 #
+# Unlock progression is mostly disabled (unlock_at_station_level = -1) pending
+# the balancing pass. The capital hulls are the exception: battleship is gated
+# to station level 1, and dreadnought (level 2) requires battleship to be
+# unlocked first (unlock_requires) — a demonstration of the prerequisite chain.
+#
 # Size classes:
 #   xs  drone                      1 cell — exactly one 1x1 module
 #   s   frigate, destroyer         no 2x2 area anywhere: only 1x1/1x2/1x3/L modules fit
@@ -19,21 +24,21 @@
 id = "drone"
 unlock_at_station_level = -1
 layout = ["O"]
-default_modules = [{type = "laser_cannon_s", x = 0, y = 0, rotation = "east"}]
+default_modules = [{type = "railgun_s", x = 0, y = 0, rotation = "east"}]
 
 [ship.schematic]
-materials = [{item = "iron_ore", amount = 1}]
-production_time_seconds = 5
+materials = [{item = "drone_hull", amount = 1}]
+production_time_seconds = 1
 
 [ship.health]
-hp = 3
+hp = 60
 
 [ship.movement]
-speed_mps = 40
-main_acceleration_mpss = 2
-maneuvering_acceleration_mpss = 1
-angular_acceleration_radpss = 12.56
-max_rotation_speed_radps = 6.28
+speed_mps = 45
+main_acceleration_mpss = 60
+maneuvering_acceleration_mpss = 30
+angular_acceleration_radpss = 12
+max_rotation_speed_radps = 6
 
 [ship.sensor]
 sensor_range_m = 150
@@ -50,18 +55,23 @@ layout = [
     "OOO",
     "XOX",
 ]
+default_modules = [
+    {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+    {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "frigate_hull", amount = 1}]
-production_time_seconds = 10
+production_time_seconds = 2
 
 [ship.health]
-hp = 30
+hp = 300
 
 [ship.movement]
-speed_mps = 30
-main_acceleration_mpss = 50
-maneuvering_acceleration_mpss = 25
+speed_mps = 35
+main_acceleration_mpss = 45
+maneuvering_acceleration_mpss = 22
 angular_acceleration_radpss = 8
 max_rotation_speed_radps = 4
 
@@ -74,23 +84,30 @@ sensor_range_m = 200
 # mount medium hardware.
 [[ship]]
 id = "destroyer"
-unlock_at_station_level = -1
+unlock_at_station_level = 0
 layout = [
     "OXOXO",
     "OOOOO",
 ]
+default_modules = [
+    {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+    {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "destroyer_hull", amount = 1}]
-production_time_seconds = 15
+production_time_seconds = 3
 
 [ship.health]
-hp = 50
+hp = 550
 
 [ship.movement]
-speed_mps = 25
-main_acceleration_mpss = 40
-maneuvering_acceleration_mpss = 20
+speed_mps = 30
+main_acceleration_mpss = 35
+maneuvering_acceleration_mpss = 18
 angular_acceleration_radpss = 6
 max_rotation_speed_radps = 3
 
@@ -103,25 +120,31 @@ sensor_range_m = 220
 # supports; no 3x3 area exists for an l gun.
 [[ship]]
 id = "cruiser"
-unlock_at_station_level = -1
+unlock_at_station_level = 2
 layout = [
     "XOOX",
     "OOOO",
     "OOOO",
     "XOOX",
 ]
+default_modules = [
+    {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+    {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+    {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "cruiser_hull", amount = 1}]
-production_time_seconds = 25
+production_time_seconds = 4
 
 [ship.health]
-hp = 120
+hp = 1500
 
 [ship.movement]
-speed_mps = 20
-main_acceleration_mpss = 30
-maneuvering_acceleration_mpss = 15
+speed_mps = 24
+main_acceleration_mpss = 25
+maneuvering_acceleration_mpss = 12
 angular_acceleration_radpss = 4
 max_rotation_speed_radps = 2
 
@@ -135,25 +158,34 @@ sensor_range_m = 250
 # stern leave no 3x3 area for an l gun and no 2x6 area for a drone hangar.
 [[ship]]
 id = "battlecruiser"
-unlock_at_station_level = -1
+unlock_at_station_level = 4
+unlock_requires = ["cruiser"]
 layout = [
     "OOXXOO",
     "OOOOOO",
     "XOOOOX",
     "XXOOXX",
 ]
+default_modules = [
+    {type = "railgun_m", x = 0, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 4, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 2, y = 3, rotation = "east"},
+    {type = "railgun_s", x = 1, y = 2, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 2, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "battlecruiser_hull", amount = 1}]
-production_time_seconds = 35
+production_time_seconds = 5
 
 [ship.health]
-hp = 180
+hp = 2400
 
 [ship.movement]
-speed_mps = 18
-main_acceleration_mpss = 25
-maneuvering_acceleration_mpss = 12
+speed_mps = 20
+main_acceleration_mpss = 20
+maneuvering_acceleration_mpss = 10
 angular_acceleration_radpss = 3
 max_rotation_speed_radps = 1.5
 
@@ -169,7 +201,8 @@ sensor_range_m = 260
 # so no 2x6 drone hangar fits.
 [[ship]]
 id = "battleship"
-unlock_at_station_level = -1
+unlock_at_station_level = 6
+unlock_requires = ["battlecruiser"]
 layout = [
     "XOOOOX",
     "OOOOOO",
@@ -177,18 +210,26 @@ layout = [
     "OOOOOO",
     "XOOOOX",
 ]
+default_modules = [
+    {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+    {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+    {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+    {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+    {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "battleship_hull", amount = 1}]
-production_time_seconds = 60
+production_time_seconds = 6
 
 [ship.health]
-hp = 350
+hp = 6300
 
 [ship.movement]
-speed_mps = 14
-main_acceleration_mpss = 18
-maneuvering_acceleration_mpss = 8
+speed_mps = 15
+main_acceleration_mpss = 14
+maneuvering_acceleration_mpss = 7
 angular_acceleration_radpss = 2
 max_rotation_speed_radps = 1
 
@@ -203,7 +244,8 @@ sensor_range_m = 280
 # stay the only hangar hull. Bow and stern strips hold supports.
 [[ship]]
 id = "dreadnought"
-unlock_at_station_level = -1
+unlock_at_station_level = 8
+unlock_requires = ["battleship"]
 layout = [
     "XXXOOOOOXXX",
     "OOOXOOOXOOO",
@@ -211,18 +253,28 @@ layout = [
     "OOOXOOOXOOO",
     "XXOOXXXOOXX",
 ]
+default_modules = [
+    {type = "railgun_l", x = 0, y = 1, rotation = "east"},
+    {type = "railgun_l", x = 4, y = 1, rotation = "east"},
+    {type = "railgun_l", x = 8, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 3, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 5, y = 0, rotation = "east"},
+    {type = "armor_plates", x = 2, y = 4, rotation = "east"},
+    {type = "armor_plates", x = 7, y = 4, rotation = "east"},
+    {type = "railgun_s", x = 7, y = 0, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "dreadnought_hull", amount = 1}]
-production_time_seconds = 120
+production_time_seconds = 8
 
 [ship.health]
-hp = 800
+hp = 24000
 
 [ship.movement]
-speed_mps = 8
-main_acceleration_mpss = 10
-maneuvering_acceleration_mpss = 5
+speed_mps = 10
+main_acceleration_mpss = 8
+maneuvering_acceleration_mpss = 4
 angular_acceleration_radpss = 1
 max_rotation_speed_radps = 0.5
 
@@ -236,7 +288,8 @@ sensor_range_m = 300
 # the lower decks hold supports and 2x2 point-defense m guns.
 [[ship]]
 id = "carrier"
-unlock_at_station_level = -1
+unlock_at_station_level = 9
+unlock_requires = ["battleship"]
 layout = [
     "XOOOOOOOOX",
     "OOOOOOOOOO",
@@ -244,18 +297,26 @@ layout = [
     "XOOOOOOOOX",
     "XXXOOOOXXX",
 ]
+default_modules = [
+    {type = "drone_hangar", x = 2, y = 0, rotation = "east"},
+    {type = "railgun_m", x = 3, y = 2, rotation = "east"},
+    {type = "railgun_m", x = 6, y = 2, rotation = "east"},
+    {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+    {type = "armor_plates", x = 8, y = 1, rotation = "east"},
+    {type = "sensor_booster", x = 3, y = 4, rotation = "east"},
+]
 
 [ship.schematic]
 materials = [{item = "carrier_hull", amount = 1}]
-production_time_seconds = 120
+production_time_seconds = 8
 
 [ship.health]
-hp = 700
+hp = 24000
 
 [ship.movement]
-speed_mps = 9
-main_acceleration_mpss = 10
-maneuvering_acceleration_mpss = 5
+speed_mps = 10
+main_acceleration_mpss = 8
+maneuvering_acceleration_mpss = 4
 angular_acceleration_radpss = 1
 max_rotation_speed_radps = 0.5
 

bin/app/data/config/stations.toml

@@ -1,10 +1,18 @@
+# stations.toml
+#
+# Combat-pass anchors (see docs/balancing/targets.md, "Combat anchors"):
+# a fresh player defence station holds one early parity wave unaided; the
+# enemy station at level 0 matches the player station exactly and scales
+# with the push level x. Station scrap drops stay authored (pushing rewards
+# are tuned independently of ship production costs, REQ-RES-SCRAP-DROP).
+
 [hq]
 surface_mask = [
   "AAA",
   "AAA",
   "AAA",
 ]
-hp_formula = "1000"
+hp_formula = "5000"
 
 [player_station]
 surface_mask = [
@@ -12,19 +20,19 @@ surface_mask = [
   "SS",
 ]
 level = 1
-hp_formula = "300"
-damage_formula = "5"
-range_m_formula = "200"
+hp_formula = "3000"
+damage_formula = "25"
+range_m_formula = "120"
 fire_rate_hz_formula = "1"
-scrap_drop_formula = "10"
+scrap_drop_formula = "40"
 
 [enemy_station]
 surface_mask = [
   "SS",
   "SS",
 ]
-hp_formula = "300 + 150*x"
-damage_formula = "2 + 1*x"
-range_m_formula = "200"
-fire_rate_hz_formula = "1.0 + 0.2*x"
-scrap_drop_formula = "10 + 5*x"
+hp_formula = "3000 + 1500*x"
+damage_formula = "25 + 12*x"
+range_m_formula = "120"
+fire_rate_hz_formula = "1.0 + 0.1*x"
+scrap_drop_formula = "40 + 30*x"

bin/app/data/config/visuals.toml

@@ -116,11 +116,11 @@ outline = "#201010"
 fill    = "#c47a3a"
 outline = "#3a1a0a"
 
-[items.titanium_ore]
-fill    = "#9aa3ad"
-outline = "#2a2e33"
+[items.quartz]
+fill    = "#e0d4f0"
+outline = "#40345a"
 
-# --- ingots ---
+# --- smelted basics ---
 
 [items.iron_ingot]
 fill    = "#b0b0b8"
@@ -130,9 +130,9 @@ outline = "#202028"
 fill    = "#d48a4a"
 outline = "#402010"
 
-[items.titanium_ingot]
-fill    = "#c8d2dc"
-outline = "#3a4048"
+[items.silicon]
+fill    = "#33415e"
+outline = "#0e1420"
 
 # --- salvage loop ---
 
@@ -140,9 +140,9 @@ outline = "#3a4048"
 fill    = "#7a7268"
 outline = "#201a14"
 
-[items.advanced_alloy]
-fill    = "#a06acc"
-outline = "#201030"
+[items.voidsteel]
+fill    = "#4a3a6a"
+outline = "#151020"
 
 # --- basic components ---
 
@@ -154,9 +154,9 @@ outline = "#3a2008"
 fill    = "#8a92a0"
 outline = "#22262c"
 
-[items.circuit_board]
-fill    = "#2ea35a"
-outline = "#0a2a14"
+[items.copper_coil]
+fill    = "#d07030"
+outline = "#381808"
 
 [items.building_block]
 fill    = "#c8b070"
@@ -164,26 +164,30 @@ outline = "#302810"
 
 # --- advanced components ---
 
-[items.mechanical_parts]
-fill    = "#6f7a66"
-outline = "#1c2018"
+[items.control_chip]
+fill    = "#2ea35a"
+outline = "#0a2a14"
 
-[items.targeting_unit]
-fill    = "#3a9e8c"
-outline = "#0c2824"
+[items.capacitor_bank]
+fill    = "#d0a030"
+outline = "#302408"
+
+[items.hardened_steel]
+fill    = "#6a7280"
+outline = "#181c22"
+
+[items.ceramic_plate]
+fill    = "#e0d8c8"
+outline = "#3a3428"
 
 [items.drive_unit]
 fill    = "#4a6ad0"
 outline = "#101a38"
 
-[items.titanium_frame]
-fill    = "#b8c4d4"
-outline = "#343c48"
-
 # --- capital components ---
 
-[items.reinforced_plating]
-fill    = "#8a6ad0"
+[items.voidsteel_plate]
+fill    = "#7a5aaa"
 outline = "#1c1038"
 
 [items.capital_core]
@@ -192,15 +196,15 @@ outline = "#280c30"
 
 # --- module items ---
 
-[items.laser_cannon_s_module]
+[items.railgun_s_module]
 fill    = "#691313"
 outline = "#f3ff4f"
 
-[items.laser_cannon_m_module]
+[items.railgun_m_module]
 fill    = "#892020"
 outline = "#f3ff4f"
 
-[items.laser_cannon_l_module]
+[items.railgun_l_module]
 fill    = "#a92d2d"
 outline = "#f3ff4f"
 
@@ -344,6 +348,9 @@ demolish_tint  = "#ff000033"   # demolish-mode hover tint
 selection_rect = "#00ff00"     # box-drag selection rectangle (REQ-UI-MULTI-SELECT)
 tile_highlight = "#ffffff22"   # tile under cursor
 selected_outline = "#ffff00"   # outline drawn around currently-selected building(s)
+copy_config    = "#33ccff66"   # copy-settings eligible-target tint + copy/paste flash (REQ-BLD-COPY-CONFIG-FEEDBACK)
+locked_asteroid = "#0000007f"  # tint over the asteroid left of the buildable edge (not yet unlocked by expansion)
+modal_dim      = "#00000099"   # semi-transparent black dim behind modal dialogs/menus (REQ-UI-MODAL-DIM)
 
 # -----------------------------------------------------------------------------
 # Schematic-drop toasts (REQ-UI-SCHEMATIC-TOAST)

bin/app/data/config/world.toml

@@ -1,15 +1,16 @@
 [world]
 height_tiles = 40
 refund_percentage = 100
-starting_building_blocks = 1000
-scrap_despawn_seconds = 30
-scrap_per_threat = 0.01
+starting_building_blocks = 200
+scrap_despawn_seconds = 120
+scrap_per_threat = 0.25
 tile_size_m = 10
 belt_speed_mps = 20
 tunnel_max_distance_tiles = 10
 departure_interval_seconds = 20
 orbit_factor = 0.8
 rally_orbit_radius_tiles = 5.0
+building_blocks_tooltip = "Building blocks are the currency for construction. Spend them to place buildings and to expand the asteroid. Produce building blocks in your factory and deliver them to the HQ on a belt to grow your stock."
 
 [regions]
 asteroid_width_tiles = 60
@@ -17,9 +18,18 @@ player_buffer_width_tiles = 20
 contest_zone_width_tiles = 60
 enemy_buffer_width_tiles = 20
 
+[scroll]
+# View pan speed (REQ-UI-SCROLL-SPEED): slow near the asteroid, fast across the
+# contest zone, with a linear ramp of the given width straddling each boundary.
+pan_speed_slow_tiles_per_second = 16.0
+pan_speed_fast_tiles_per_second = 32.0
+pan_ramp_band_width_tiles = 16
+
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+# x = expansions already purchased; ~1 per cycle mid-game, decelerating
+# to 2-3 cycles late (docs/balancing/derived.md).
+cost_building_blocks_formula = "300 + 50*x + 10*x*x"
 
 [push]
 push_expand_columns_tiles = 10
@@ -32,10 +42,13 @@ target_hysteresis         = 0.40                   # keep current target unless
 
 [artifacts]
 artifact_chance_formula = "0.05 * x"  # 5% chance per station level
-artifact_win_count      = 3
+artifact_win_count      = 5
 
 [waves]
-threat_rate_formula = "x"
+# Tuned against the factory-size curve (docs/balancing/targets.md, balancing
+# targets): stays below the player's achievable military output early,
+# crosses it around the late boundary (~cycle 15), overwhelms by ~24.
+threat_rate_formula = "2*x + 0.15*x*x"
 gap_min_seconds = 15
 gap_max_seconds = 45
 spawn_duration_seconds = 10

bin/balancing/data/balancing.toml

@@ -1,68 +1,397 @@
+# balancing.toml — canonical arena suite for the combat stats pass.
+#
+# Ship counts are chosen so both teams have (near-)equal total threat,
+# using the verified fitted threat values from tools/threat_report.py:
+#   drone 10.5, frigate 47, destroyer 99, cruiser 233.5,
+#   battlecruiser 354.5, battleship 722.5, dreadnought 1491.5,
+#   carrier 1436.5, glass destroyer (8 small guns) 92, repair drone 17.
+# Module arrays mirror the ships' default_modules loadouts unless a
+# doctrine variant is the point of the arena.
+#
+# Expectations: mirror matches and equal-threat cross-tier matchups should
+# be near-draws (power-per-threat rule); the two-to-one arena must be a
+# decisive win for the larger team. "Cruisers vs carrier" is EXPECTED to be
+# a loss for the carrier until the drone-launching capability exists — the
+# hangar is 224 threat of dead weight.
+
+# --- mirrors (sanity: symmetric outcomes, fight duration in the 30-60 s band) ---
+
 [[arena]]
-name = "Fighters vs Sniper"
-height_tiles = 20
+name = "Mirror: drones 20v20"
+height_tiles = 10
 player_buffer_width_tiles = 10
-contest_zone_width_tiles = 60
+contest_zone_width_tiles = 50
 enemy_buffer_width_tiles = 10
 
   [[arena.team]]
   name = "Alpha"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 5
+    count = 20
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
   [[arena.team]]
   name = "Beta"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 2
+    count = 20
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_stabilizer",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_stabilizer",  x = 1, y = 1, rotation = "east"},
-      {type = "weapon_upgrade",  x = 1, y = 1, rotation = "east"},
-      {type = "sensor_booster",  x = 1, y = 1, rotation = "east"},
-      {type = "sensor_booster",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
 [[arena]]
-name = "Fighters vs Supported"
-height_tiles = 20
+name = "Mirror: cruisers 6v6"
+height_tiles = 10
 player_buffer_width_tiles = 10
-contest_zone_width_tiles = 60
+contest_zone_width_tiles = 50
 enemy_buffer_width_tiles = 10
 
   [[arena.team]]
-  name = "Fighters"
+  name = "Alpha"
     [[arena.team.ship]]
-    schematic = "drone"
-    count = 5
+    schematic = "cruiser"
+    count = 6
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
     ]
 
   [[arena.team]]
-  name = "Supported"
+  name = "Beta"
     [[arena.team.ship]]
-    schematic = "drone"
-    count = 3
+    schematic = "cruiser"
+    count = 6
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
     ]
 
+[[arena]]
+name = "Mirror: battleships 2v2"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Alpha"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 2
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Beta"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 2
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+# --- equal-threat cross-tier matchups (power-per-threat: expect near-draws) ---
+
+[[arena]]
+name = "Drone swarm vs cruisers (462 vs 467)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Swarm"
+    [[arena.team.ship]]
+    schematic = "drone"
+    count = 44
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Cruisers"
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 2
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Frigates vs battleship (705 vs 723)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Frigates"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 15
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Battleship"
+    [[arena.team.ship]]
+    schematic = "battleship"
+    count = 1
+    modules = [
+      {type = "railgun_l", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 1, y = 3, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 3, rotation = "east"},
+      {type = "weapon_stabilizer", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Destroyers vs dreadnought (1485 vs 1492)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Destroyers"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 15
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Dreadnought"
+    [[arena.team.ship]]
+    schematic = "dreadnought"
+    count = 1
+    modules = [
+      {type = "railgun_l", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_l", x = 4, y = 1, rotation = "east"},
+      {type = "railgun_l", x = 8, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 3, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 5, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 2, y = 4, rotation = "east"},
+      {type = "armor_plates", x = 7, y = 4, rotation = "east"},
+      {type = "railgun_s", x = 7, y = 0, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Cruisers vs carrier (1401 vs 1437, carrier expected to lose)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Cruisers"
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 6
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Carrier"
+    [[arena.team.ship]]
+    schematic = "carrier"
+    count = 1
+    modules = [
+      {type = "drone_hangar", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 3, y = 2, rotation = "east"},
+      {type = "railgun_m", x = 6, y = 2, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 8, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 4, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Mixed mid vs battlecruisers (1394 vs 1418)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Mixed"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 7
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+    [[arena.team.ship]]
+    schematic = "cruiser"
+    count = 3
+    modules = [
+      {type = "railgun_m", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 1, y = 0, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 1, y = 3, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Battlecruisers"
+    [[arena.team.ship]]
+    schematic = "battlecruiser"
+    count = 4
+    modules = [
+      {type = "railgun_m", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_m", x = 2, y = 1, rotation = "east"},
+      {type = "armor_plates", x = 2, y = 3, rotation = "east"},
+      {type = "railgun_s", x = 1, y = 2, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 2, rotation = "east"},
+    ]
+
+# --- asymmetric checks ---
+
+[[arena]]
+name = "Two to one (must be decisive)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Six"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 6
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Three"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 3
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Armored vs glass destroyers (1188 vs 1196)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Armored"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 12
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "armor_plates", x = 0, y = 1, rotation = "east"},
+      {type = "sensor_booster", x = 3, y = 1, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Glass"
+    [[arena.team.ship]]
+    schematic = "destroyer"
+    count = 13
+    modules = [
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 3, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 4, y = 1, rotation = "east"},
+    ]
+
+[[arena]]
+name = "Repair escort vs raw numbers (444 vs 444)"
+height_tiles = 10
+player_buffer_width_tiles = 10
+contest_zone_width_tiles = 50
+enemy_buffer_width_tiles = 10
+
+  [[arena.team]]
+  name = "Escorted"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 8
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
+    [[arena.team.ship]]
+    schematic = "drone"
+    count = 4
+    modules = [
+      {type = "repair_tool", x = 0, y = 0, rotation = "east"},
+    ]
+
+  [[arena.team]]
+  name = "Raw"
+    [[arena.team.ship]]
+    schematic = "frigate"
+    count = 9
+    modules = [
+      {type = "railgun_s", x = 1, y = 0, rotation = "east"},
+      {type = "railgun_s", x = 2, y = 1, rotation = "east"},
+      {type = "maneuvering_thrusters", x = 0, y = 1, rotation = "east"},
+    ]
     [[arena.team.ship]]
     schematic = "drone"
     count = 2
     modules = [
-      {type = "repair_tool",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
 
 [[arena]]
-name = "Stations and Ships"
-height_tiles = 60
+name = "Station assault (2 stations + 105 vs 315)"
+height_tiles = 10
 player_buffer_width_tiles = 15
 contest_zone_width_tiles = 40
 enemy_buffer_width_tiles = 15
@@ -71,9 +400,9 @@ enemy_buffer_width_tiles = 15
   name = "Fortified"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 3
+    count = 10
     modules = [
-      {type = "laser_cannon_s",   x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]
     [[arena.team.station]]
     type = "player_station"
@@ -90,7 +419,7 @@ enemy_buffer_width_tiles = 15
   name = "Swarm"
     [[arena.team.ship]]
     schematic = "drone"
-    count = 8
+    count = 30
     modules = [
-      {type = "laser_cannon_s",  x = 1, y = 1, rotation = "east"},
+      {type = "railgun_s", x = 0, y = 0, rotation = "east"},
     ]

bin/test/data/config/buildings.toml

@@ -83,6 +83,8 @@ id = "salvage_bay"
 cost = 25
 player_placeable = true
 construction_time_seconds = 15
+output_buffer_capacity = 20
+tooltip = "Drop-off point for salvage ships."
 surface_mask = [
   "SAA",
   "SAA>",

bin/test/data/config/modules.toml

@@ -1,5 +1,6 @@
 [[module]]
 id = "armor_plate"
+tooltip = "Adds a large flat bonus to hit points."
 unlock_at_station_level = -1
 surface_mask = ["OO"]
 materials = [{item = "iron_ingot", amount = 2}]

bin/test/data/config/recipes.toml

@@ -92,3 +92,60 @@ duration_seconds = 3.0
   item = "advanced_alloy"
   amount = 1
   probability = 0.1
+
+# -------------------------------------------------------------------
+# Extra recipes for ThreatCostCalculator unit tests (fixes 6-9)
+# -------------------------------------------------------------------
+
+# Fix 6: scrap-consuming smelter recipe for iron_ingot. Because iron_ingot
+# already has a scrap-free smelter recipe above, this recipe must be excluded
+# from iron_ingot's threat computation.
+[[recipe]]
+id = "scrap_iron"
+building = "smelter"
+inputs = [{item = "scrap", amount = 1}]
+outputs = [{item = "iron_ingot", amount = 1}]
+duration_seconds = 1.0
+
+# Fix 7: a recipe that produces 2 items per cycle. Per-unit threat must
+# divide by the output amount.
+# dual_wire: (duration=3.0 + iron_ore(1.0)*1) / 2 = 4.0 / 2 = 2.0 per unit.
+[[recipe]]
+id = "dual_wire"
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 1}]
+outputs = [{item = "dual_wire", amount = 2}]
+duration_seconds = 3.0
+
+# Fix 8: an item downstream of a reprocessing-only item (advanced_alloy).
+# advanced_alloy is resolved only by the reprocessing pass; downstream_product
+# can only resolve in a non-reprocessing pass that runs AFTER the reprocessing
+# pass, requiring proper fixpoint iteration.
+# downstream_product: 2.0 + advanced_alloy(80.0)*1 = 82.0
+[[recipe]]
+id = "downstream_product"
+building = "assembler"
+inputs = [{item = "advanced_alloy", amount = 1}]
+outputs = [{item = "downstream_product", amount = 1}]
+duration_seconds = 2.0
+
+# Fix 9: two recipes producing the same staggered_item. The cheap recipe
+# resolves before circuit_board is known; the expensive one requires
+# circuit_board. The item must be committed only once BOTH are computable,
+# so the result is max(cheap, expensive).
+# staggered_item_cheap:  1.0 + iron_ore(1.0)*1  =  2.0  (resolves early)
+# staggered_item_expensive: 1.0 + circuit_board(28.0)*1 = 29.0 (resolves later)
+# expected: max = 29.0
+[[recipe]]
+id = "staggered_item_cheap"
+building = "assembler"
+inputs = [{item = "iron_ore", amount = 1}]
+outputs = [{item = "staggered_item", amount = 1}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "staggered_item_expensive"
+building = "assembler"
+inputs = [{item = "circuit_board", amount = 1}]
+outputs = [{item = "staggered_item", amount = 1}]
+duration_seconds = 1.0

bin/test/data/config/world.toml

@@ -10,6 +10,7 @@ tunnel_max_distance_tiles = 10
 departure_interval_seconds = 20
 orbit_factor = 0.8
 rally_orbit_radius_tiles = 5.0
+building_blocks_tooltip = "Spend building blocks to build; deliver them to the HQ to gain more."
 
 [regions]
 asteroid_width_tiles = 40
@@ -17,9 +18,14 @@ player_buffer_width_tiles = 10
 contest_zone_width_tiles = 30
 enemy_buffer_width_tiles = 15
 
+[scroll]
+pan_speed_slow_tiles_per_second = 8.0
+pan_speed_fast_tiles_per_second = 24.0
+pan_ramp_band_width_tiles = 16
+
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20

cmake/version.cmake

@@ -0,0 +1,60 @@
+# simple check for a git repo
+if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+	find_package(Git)
+
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} rev-parse --abbrev-ref HEAD
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_BRANCH
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} log -1 --format=%h
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_HASH
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} log -1 --format=%ci
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_TIME
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} describe --long --match "[0-9]*" HEAD
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_VERSION_NUMBER
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+    string(REGEX REPLACE "^([0-9]+)\\..*" "\\1" VERSION_MAJOR "${GIT_VERSION_NUMBER}")
+    string(REGEX REPLACE "^[0-9]+\\.([0-9]+).*" "\\1" VERSION_MINOR "${GIT_VERSION_NUMBER}")
+    string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.([0-9]+).*" "\\1" VERSION_PATCH "${GIT_VERSION_NUMBER}")
+    string(REGEX REPLACE "^[0-9]+\\.[0-9]+\\.[0-9]+-([0-9]+).*" "\\1" VERSION_COMMIT "${GIT_VERSION_NUMBER}")
+
+else(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+    set(GIT_BRANCH "")
+    set(GIT_COMMIT_HASH "")
+    set(GIT_VERSION_NUMBER "")
+    set(VERSION_MAJOR "0")
+    set(VERSION_MINOR "0")
+    set(VERSION_PATCH "0")
+    set(VERSION_COMMIT "0")
+    set(BUILD_TYPE "")
+
+endif(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+
+set(VERSION_STRING "${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}.${VERSION_COMMIT}")
+
+message(STATUS "Version: ${VERSION_STRING}")
+
+# message(STATUS "Git current branch: ${GIT_BRANCH}")
+# message(STATUS "Git version number: " ${GIT_VERSION_NUMBER} )
+# message(STATUS "Git commit hash: ${GIT_COMMIT_HASH}")
+# message(STATUS "Git commit time: ${GIT_COMMIT_TIME}")
+# message(STATUS "Version major: ${VERSION_MAJOR}")
+# message(STATUS "Version minor: ${VERSION_MINOR}")
+# message(STATUS "Version patch: ${VERSION_PATCH}")
+# message(STATUS "Version commit: ${VERSION_COMMIT}")

cmake/version.rc.in

@@ -0,0 +1,35 @@
+// Windows version resource. Generated by CMake via configure_file() from this
+// template; @VAR@ placeholders are filled from cmake/version.cmake (version
+// numbers) and the product identity variables in the top-level CMakeLists.txt.
+// Shows up on the executable's Details tab (right-click -> Properties).
+
+#include <windows.h>
+
+VS_VERSION_INFO VERSIONINFO
+    FILEVERSION     @VERSION_MAJOR@,@VERSION_MINOR@,@VERSION_PATCH@,@VERSION_COMMIT@
+    PRODUCTVERSION  @VERSION_MAJOR@,@VERSION_MINOR@,@VERSION_PATCH@,@VERSION_COMMIT@
+    FILEFLAGSMASK   VS_FFI_FILEFLAGSMASK
+    FILEFLAGS       0x0L
+    FILEOS          VOS_NT_WINDOWS32
+    FILETYPE        VFT_APP
+    FILESUBTYPE     VFT2_UNKNOWN
+BEGIN
+    BLOCK "StringFileInfo"
+    BEGIN
+        BLOCK "040904b0"                       // US English (0x0409), Unicode (0x04b0)
+        BEGIN
+            VALUE "CompanyName",      "@PRODUCT_COMPANY@"
+            VALUE "FileDescription",  "@PRODUCT_DISPLAY_NAME@"
+            VALUE "FileVersion",      "@VERSION_STRING@"
+            VALUE "InternalName",     "@PRODUCT_NAME@"
+            VALUE "OriginalFilename", "@PRODUCT_NAME@.exe"
+            VALUE "ProductName",      "@PRODUCT_DISPLAY_NAME@"
+            VALUE "ProductVersion",   "@VERSION_STRING@"
+            VALUE "LegalCopyright",   "@PRODUCT_COPYRIGHT@"
+        END
+    END
+    BLOCK "VarFileInfo"
+    BEGIN
+        VALUE "Translation", 0x409, 1200       // 0x409 = en-US, 1200 = Unicode code page
+    END
+END

docs/balancing/README.md

@@ -0,0 +1,56 @@
+# Balancing Documentation
+
+Everything about balancing Dota Factory, separated by role:
+
+- **[rules.md](rules.md)** — the design rules and principles. Timeless;
+  changes only when the design changes.
+- **[targets.md](targets.md)** — the base numbers (roots/anchors) chosen
+  by design. Change these first; everything else re-derives.
+- **[derived.md](derived.md)** — the current tuned state of all derived
+  numbers, mirroring the configs. Updated whenever configs change.
+- **[process.md](process.md)** — how balancing is done: the pass order,
+  tuning discipline, tools, and the checklist for the next round.
+- **[history.md](history.md)** — chronological record of decisions,
+  findings, bugs, and arena rounds.
+
+Related: game content (hull grids, footprint gating, tree design and
+fiction) in [../content_design.md](../content_design.md); rules with
+REQ-* ids in [../requirements.md](../requirements.md).
+
+## Status
+
+First full balancing round complete (2026-07-06): targets → tree →
+numbers → threat-calculator parity → combat stats (arena-converged) →
+pacing. Next step: full-game playtests against the run-shape targets in
+`targets.md`.
+
+## Open action items
+
+Agreed changes that require edits to `requirements.md`, the code, or the
+configs. Completed items are removed (their outcomes live in
+`requirements.md`, `history.md`, and the git history).
+
+1. **Fill unfillable schematic slots with artifacts.** With duplicates
+   removed, the schematic drop pool can run dry — previously unreachable.
+   Decision: every slot in the choice dialog that cannot be filled with a
+   schematic because the eligible pool is exhausted is filled with an
+   artifact option instead (in addition to any artifact option granted by
+   the regular artifact roll). A push therefore always awards a full
+   dialog. Update REQ-DEF-SCHEMATIC-DROP.
+2. **Confirm wave scaling in playtests.** `threat_rate_formula` is the
+   only time-scaling axis; verify the tuned curve (see `derived.md`)
+   produces the intended difficulty race in real runs.
+3. **Gate shortcut-recipe drops on their inputs.** Extend the assembler
+   recipe schematic pool eligibility in REQ-DEF-SCHEMATIC-DROP: in
+   addition to the existing station-level and output-item checks, all of
+   the recipe's input item types must be implicitly unlocked as well.
+4. **Resource deposits.** Add a terrain deposit layer per the Resource
+   deposits rules (`rules.md`): deposit patches generated in expansion
+   columns (deterministic content per expansion, randomized placement
+   within the new columns), deposit rendering, and a miner condition (a
+   resource recipe is selectable only if the miner's footprint overlaps
+   at least one matching deposit tile). Touches REQ-BLD-MINER ("every
+   asteroid tile is equivalent" no longer holds),
+   REQ-GW-ASTEROID-EXPAND / REQ-EXP-*, `world.toml`, and `visuals.toml`.
+   Until this lands, quartz mines anywhere and the mid-game is
+   knowledge-gated only.

docs/balancing/derived.md

@@ -0,0 +1,164 @@
+# Derived Values (current tuned state)
+
+Everything here is derived from `targets.md` under the rules in
+`rules.md`, and mirrors the config files. Item threats, ship threats,
+ratios, and belt checks are verified by `tools/threat_report.py` — re-run
+it after any recipe or material change and update this file when values
+move. Combat stats were tuned empirically against the arena suite in
+`bin/balancing/data/balancing.toml` (round-by-round record in
+`history.md`).
+
+## Economy constants
+
+- `scrap_per_threat = 0.25` — 1 scrap per 4 threat destroyed (a cruiser
+  kill drops ~59 scrap); threat(scrap) = 4.
+- Scrap smelting: 1 scrap → 1 iron_ingot, 1 s — deliberately
+  value-losing; reprocessing is the value-preserving path.
+- Reprocessing: 4 scrap per cycle, 4 s; full-pool weights iron_ingot 30 /
+  copper_ingot 30 / silicon 20 / voidsteel 20 → threat(voidsteel)
+  = (4·4 + 4)/0.2 = 100.
+- `scrap_despawn_seconds = 120` (a capital kill drops hundreds of scrap,
+  collected one per salvage cycle).
+
+## Recipes and item threats
+
+(dur in seconds; threat is per output unit)
+
+| item | recipe | dur | out | threat |
+|---|---|---|---|---|
+| iron_ore / copper_ore | miner | 1 | 1 | 1 |
+| quartz | miner (deposit) | 2 | 1 | 2 |
+| iron_ingot | 1 iron_ore | 1 | 1 | 2 |
+| copper_ingot | 1 copper_ore | 1 | 1 | 2 |
+| silicon | 1 quartz | 2 | 1 | 4 |
+| steel_plate | 2 iron_ingot | 3 | 1 | 7 |
+| copper_wire | 1 copper_ingot | 1 | 2 | 1.5 |
+| copper_coil | 2 copper_wire | 1.5 | 1 | 4.5 |
+| building_block | 2 steel_plate | 2 | 4 | 4 |
+| control_chip | 1 silicon + 2 copper_wire | 5 | 1 | 12 |
+| capacitor_bank | 2 copper_coil + 1 silicon | 5 | 1 | 18 |
+| hardened_steel | 3 steel_plate | 12 | 1 | 33 |
+| ceramic_plate | 2 quartz | 4 | 1 | 8 |
+| drive_unit | 2 steel_plate + 2 copper_coil + 1 control_chip | 8 | 1 | 43 |
+| voidsteel_plate | 1 voidsteel + 1 hardened_steel | 8 | 1 | 141 |
+| capital_core | 2 voidsteel + 1 capacitor_bank + 1 control_chip | 10 | 1 | 240 |
+
+Shortcut recipes (drop-only; item threat stays defined by the base path
+via the max rule): `shortcut_steel_plate` 3 iron_ore → 1 plate (2 s,
+level 1), `shortcut_control_chip` 2 quartz → 1 chip (4 s, level 2),
+`shortcut_hardened_steel` 4 iron_ingot → 1 hardened (8 s, level 2).
+
+Ratio curve realized: t1 all 1:1 (miner:smelter); t2 clean 2:3
+(ingot→plate, wire→coil); t3 strange — 2:5 (silicon→chip), 3:5
+(coil→capacitor), 3:4 (plate→hardened, plate→drive); t4 inverted 3:2
+(hardened→voidsteel_plate). Belt check: worst input demand 1.33 items/s,
+under the ~2/s single-belt cap everywhere.
+
+## Module prefabs
+
+(contribution = item threat + module production time)
+
+| module | recipe | dur | mod. time | contribution |
+|---|---|---|---|---|
+| railgun_s | 1 copper_coil | 1 | 1 | 6.5 |
+| salvager | 1 steel_plate + 2 copper_wire | 2 | 1 | 13 |
+| repair_tool | 1 steel_plate + 2 copper_wire | 2 | 1 | 13 |
+| armor_plates | 4 steel_plate | 3 | 1 | 32 |
+| maneuvering_thrusters | 1 steel_plate + 1 copper_coil | 2 | 1 | 14.5 |
+| sensor_booster | 2 copper_wire + 1 copper_coil | 2 | 1 | 10.5 |
+| afterburner | 2 copper_coil + 1 steel_plate | 3 | 1 | 20 |
+| weapon_stabilizer | 1 steel_plate + 1 copper_coil | 2 | 1 | 14.5 |
+| weapon_primer | 1 capacitor_bank + 1 copper_coil | 4 | 2 | 28.5 |
+| weapon_upgrade | 1 control_chip + 1 copper_coil | 4 | 2 | 22.5 |
+| railgun_m | 1 capacitor_bank + 2 steel_plate + 1 copper_coil | 4 | 3 | 43.5 |
+| drone_bay | 1 control_chip + 2 steel_plate + 1 copper_coil | 4 | 3 | 37.5 |
+| railgun_l | 1 capacitor_bank + 2 hardened_steel + 1 ceramic_plate | 6 | 4 | 102 |
+| drone_hangar | 1 voidsteel_plate + 2 control_chip + 1 drive_unit | 10 | 6 | 224 |
+
+## Ships
+
+(fitted = hull item + ship base time + default loadout; the default
+loadouts are the `default_modules` used by enemy waves and are
+geometry-validated against the hull grids)
+
+| ship | hull recipe | dur | base | default loadout | fitted |
+|---|---|---|---|---|---|
+| drone | 1 iron_ingot | 1 | 1 | railgun_s | 10.5 |
+| frigate | 2 steel_plate + 1 copper_wire | 2 | 2 | 2× railgun_s, maneuvering_thrusters | 47 |
+| destroyer | 3 steel_plate + 2 copper_coil | 4 | 3 | 3× railgun_s, armor_plates, sensor_booster | 99 |
+| cruiser | 2 hardened_steel + 2 control_chip | 6 | 4 | 2× railgun_m, armor_plates, maneuvering_thrusters | 233.5 |
+| battlecruiser | 3 hardened_steel + 2 control_chip + 1 drive_unit | 8 | 5 | 3× railgun_m, armor_plates, 2× railgun_s | 354.5 |
+| battleship | 3 voidsteel_plate + 1 drive_unit + 2 control_chip | 10 | 6 | railgun_l, 2× railgun_m, weapon_stabilizer, 2× railgun_s | 722.5 |
+| dreadnought | 5 voidsteel_plate + 1 capital_core + 2 drive_unit | 12 | 8 | 3× railgun_l, 4× armor_plates, railgun_s | 1491.5 |
+| carrier | 5 voidsteel_plate + 1 capital_core + 2 drive_unit | 12 | 8 | drone_hangar, 2× railgun_m, 2× armor_plates, sensor_booster | 1436.5 |
+
+## Combat stats
+
+(arena-converged, 2026-07; see `history.md` rounds 1–5)
+
+**Weapons:** railgun_s 2 dmg × 2.0 Hz (4.0 DPS), range 50 m;
+railgun_m 14 × 1.5 (21), range 70; railgun_l 52 × 0.8 (41.6), range 100.
+
+**Hull HP** (15/threat prior + empirical trims): drone 60, frigate 300,
+destroyer 550, cruiser 1500, battlecruiser 2400, battleship 6300,
+dreadnought/carrier 24000.
+
+**Mobility ladder** (speed m/s | main accel | maneuvering | angular |
+max rot): drone 45|60|30|12|6, frigate 35|45|22|8|4,
+destroyer 30|35|18|6|3, cruiser 24|25|12|4|2, battlecruiser 20|20|10|3|1.5,
+battleship 15|14|7|2|1, dreadnought/carrier 10|8|4|1|0.5.
+Sensors: 150/200/220/250/260/280/300/350 m.
+
+**Other modules:** armor_plates +1200 HP; repair_tool 9 HP × 1 Hz,
+range 80; salvager range 60, cargo 20, 0.5 collections/s; afterburner
+×1.6 speed +60 accel; maneuvering_thrusters ×1.2 speed +10 maneuvering;
+sensor_booster +50 m; weapon_upgrade ×1.2 damage; weapon_primer ×1.2
+rate; weapon_stabilizer ×1.3 range ×0.8 rate.
+
+**Stations:** HQ 5000 HP. Player station 3000 HP, 25 dmg × 1 Hz,
+range 120, scrap 40. Enemy station: 3000+1500x HP, 25+12x dmg,
+1.0+0.1x Hz, range 120, scrap 40+30x (x = push level).
+
+## Pacing
+
+**Unlock ladder** (level → unlocks; ← marks `unlock_requires`; starting
+set at −1: drone, frigate, railgun_s, salvager, building_block recipe):
+
+| level | ships | modules | recipes |
+|---|---|---|---|
+| 0 | destroyer | repair_tool, armor_plates | |
+| 1 | | maneuvering_thrusters, sensor_booster | shortcut_steel_plate |
+| 2 | cruiser | railgun_m, afterburner | shortcut_control_chip, shortcut_hardened_steel |
+| 3 | | weapon_stabilizer | |
+| 4 | battlecruiser ← cruiser | weapon_primer, weapon_upgrade | |
+| 5 | | drone_bay | |
+| 6 | battleship ← battlecruiser | railgun_l ← railgun_m | |
+| 8 | dreadnought ← battleship | | |
+| 9 | carrier ← battleship | drone_hangar | |
+
+Level 0's pool has exactly three entries (a full first dialog). Level 2
+is the quartz gate: cruiser and railgun_m are the first schematics whose
+chains reach quartz; the shortcut outputs only become implicitly
+unlocked alongside them, so shortcuts cannot drop early.
+
+**Threat rate** `2*x + 0.15*x*x` (x = boss cycle counter), against the
+factory-size curve with ~half the player's output assumed military:
+
+| cycle x | rate (threat/s) | player military (≈ curve/2) |
+|---|---|---|
+| 2 | 4.6 | ~12 |
+| 6 | 17.4 | ~30 |
+| 15 | 63.8 | ~60 |
+| 20 | 100 | ~75 |
+| 24 | 134 | — |
+
+**Economy:** `starting_building_blocks = 200`; expansion cost formula
+`300 + 50*x + 10*x*x` (x = expansions already purchased: ~1 affordable
+per cycle mid-game at ~1/3 of block income, stretching to 2–3 cycles
+late — quadratic so costs outrun the roughly linear block income
+gradually, never with a hard wall); `artifact_win_count = 5` with
+`artifact_chance_formula = 0.05*x`. Building costs: belt 2, splitter 3,
+tunnels 5, miner 15, smelter 20, assembler 35, reprocessing plant 40,
+salvage bay 25, shipyard 60 — averaging ≈18 blocks per placed building
+(belts included), which meets the 4-minute doubling target at block
+threat 4.

docs/balancing/history.md

@@ -0,0 +1,96 @@
+# Balancing History
+
+Chronological record of the balancing work: what was decided, what was
+found, what changed. Current values live in `derived.md`; this file
+explains how they got there.
+
+## 2026-07-02/03 — rules and structural decisions
+
+- Rules document written (now `rules.md`): ratio curve, shortcut
+  recipes, refactorability, cost archetypes, threat model, growth curve.
+- Scrap derived from threat (`scrap_per_threat`), replacing authored
+  per-ship scrap drops; scrap threat became the constant
+  `1/scrap_per_threat`, removing the old min-scrap_drop derivation and
+  its circularity.
+- Duplicate schematic drops removed (no level-ups); ship/module levels
+  removed entirely — all time scaling lives in the threat rate, push
+  scaling stays on stations. Mk2 upgrade recipes noted as the future
+  per-item progression.
+- Growth-curve rules added: escalating expansion costs, designed
+  doubling time, growth limited by economy not waiting; resource
+  deposits designed (deposit-gated mid resource in expansion territory).
+- Production tree v2 decided: iron/copper everywhere (M-type asteroid),
+  quartz in geodes (mid), voidsteel battle-forged from scrap (late);
+  titanium dropped; lasers renamed to railguns, lasers reserved as a
+  future weapon type.
+
+## 2026-07-03 — targets, tree, numbers
+
+- Balancing targets fixed: ≤2 h run, phases 1–5/6–14/15+, factory curve
+  25/60/120/150, threat ladder, 25-ship swarm, block roots.
+- Tree structure drafted and numbers computed (recursive threat
+  calculator); ratio curve realized; fitted ships within 96–124% of the
+  strawman ladder (small end hot from fixed chain overhead — ladder
+  later adopted the achieved values).
+- **Rule bugs found by the numbers work:** the scrap→ingot smelter
+  recipe would inflate basic materials via the max rule (fixed:
+  scrap-consuming recipes are threat fallback only); recipe output
+  amounts were ignored (fixed: per-unit division); items downstream of
+  reprocessing-only items never resolved (fixed: fixpoint resolution);
+  a shortcut recipe resolving earlier than the base path silently
+  underpriced items (fixed: commit only when all eligible recipes are
+  computable). All four fixed in `ThreatCostCalculator` with tests, and
+  implemented in `tools/threat_report.py`.
+- v2 tree written into the configs; `default_modules` loadouts
+  geometry-validated (the numbers-pass loadouts for battlecruiser and
+  dreadnought were geometrically impossible — L-modifiers don't fit
+  beside full gun complements; corrected loadouts landed closer to the
+  ladder).
+
+## 2026-07-04 — combat stats, arena rounds 1–5
+
+Initial stats derived from the anchors (weapon DPS ≈0.6/threat flat,
+hull 15 HP/threat, armor 20/threat, repair 2 HP/s/threat, station
+range 200).
+
+- **Round 1:** concentrated fleets won all equal-threat cross-tier
+  matchups flawlessly; glass beat armored; repair escort flawless; two
+  stations shrugged off a 3× swarm. Changes: concentration tax on m/l
+  gun damage (railgun_m 17→14, railgun_l 70→52), armor 640→1000,
+  repair 25→12, station range 200→120. (Team-1 "bias" in mirrors later
+  shown to be noise.)
+- **Round 2 (EHP-margin logging added):** battleship +33% while
+  dreadnought −37% (stabilizer range + opposing armor); glass still
+  +11%. Changes: stabilizer range ×1.5→×1.3; per-hull trims introduced
+  (BC 2700→2500, BS 7500→7000, DN/CV 15500→19000).
+- **Round 3 (narrow lanes — geometry fixed into the fixture):**
+  DN closed to −11%, BS +22%, swarm flipped to +14% over cruisers,
+  glass +12% third time. Changes: armor 1000→1200, BC 2500→2000,
+  BS 7000→6300, DN/CV 19000→22500.
+- **Round 4:** glass-vs-armored resolved (+3% armored); noise floor
+  established (~±10%/run: BS ignored a −10% EHP cut; repair drifted
+  14→24% untouched). Convergence policy adopted: two-round signals only,
+  ±20% converged. Changes: BC 2000→2200, DN/CV 22500→24000; BS +23%
+  accepted as doctrine texture (mechanical range edge vs. pure small
+  fleets).
+- **Round 5 (durations logged; end-condition bug fixed upstream):**
+  TTK anchor validated (mirrors 23/71/95 s; DN-vs-swarm 214 s outlier
+  accepted); dreadnought +3%, everything else inside band. Final
+  changes: BC 2200→2400, repair 12→9 (persistent +24% escort margin).
+  **Combat pass declared converged.**
+
+## 2026-07-05/06 — pacing pass
+
+- Unlock ladder set (starting set drone/frigate/railgun_s/salvager;
+  quartz gate at level 2; capitals at 8–9 with `unlock_requires`
+  chains); threat rate `2*x + 0.15*x*x`; starting blocks 1000→200;
+  expansion 400 flat pending the cost formula; artifacts 3→5.
+- **Bug found:** the building_block recipe was silently locked at game
+  start (building blocks appear in no schematic's materials, so implicit
+  unlocking could never reach the recipe) — fixed with an explicit
+  `unlock_at_station_level = -1`.
+- Expansion cost formula implemented and set (`300 + 50*x + 10*x*x`):
+  quadratic, so costs outrun the roughly linear block income gradually
+  — ~1 expansion per cycle mid-game, 2–3 cycles apart late.
+- **First full balancing round complete.** Next: full-game playtests
+  against the run-shape targets.

docs/balancing/process.md

@@ -0,0 +1,98 @@
+# Balancing Process
+
+How balancing is done in this project: the pass order, the tuning
+discipline, and the tools. Refer to this when starting the next
+balancing round.
+
+## The pass order
+
+Each pass depends on the ones before it; a change in an earlier pass
+invalidates the later ones (but not vice versa). Redo from the earliest
+pass whose inputs changed.
+
+1. **Targets** (`targets.md`) — choose the root numbers: run shape,
+   factory curve, threat-cost ladder, fleet size, block roots, combat
+   anchors, pacing anchors. These are design decisions, not
+   measurements. Everything else is derived from them.
+2. **Tree structure** (`../content_design.md`) — items, chains,
+   what-consumes-what, per the production tree rules (one input per
+   phase transition, generic parts, archetypes, refactorability).
+   Structure only, no quantities.
+3. **Numbers** (`derived.md`, recipes/materials in the configs) —
+   quantities and durations so every fitted ship sums to its ladder
+   value, the ratio curve is realized, and the belt/buffer guardrails
+   hold. Verified computationally by `tools/threat_report.py`.
+4. **Calculator/tooling parity** — the game's `ThreatCostCalculator`
+   and `tools/threat_report.py` must produce identical values; the
+   Python tool is the design reference. Any semantic change to
+   REQ-THREAT-* needs both updated plus tests.
+5. **Combat stats** (arena-driven) — derive stats from the combat
+   anchors, then iterate against the arena suite
+   (`bin/balancing/data/balancing.toml`) until equal-threat matchups are
+   near-draws. Threat costs are stat-independent, so arena ship counts
+   stay valid across stat changes.
+6. **Pacing** — unlock ladder, `unlock_requires` edges, threat rate,
+   block/artifact/expansion values, per the pacing anchors.
+
+Then: **full-game playtests**, which are the only check for the pacing
+pass and feed back into targets.
+
+## Tuning discipline (learned in arena rounds 1–5)
+
+- **Change anchors, not symptoms.** When a class of results is off,
+  adjust the anchor that explains all of them (e.g. the concentration
+  tax) rather than individual stats.
+- **Fewest knobs per round.** Attribution dies when many knobs move at
+  once. Prefer one anchor change plus its mechanical compensations.
+- **Shared vs. local knobs.** Guns and module stats are shared across
+  many hulls — changing them moves many matchups. Per-hull HP moves
+  exactly one matchup; it is the designated per-ship trim knob on top of
+  the HP-per-threat prior.
+- **Mind the ride-alongs.** A module buff lands on every default loadout
+  containing it (e.g. an armor buff strengthens the destroyer swarm that
+  opposes the dreadnought). Compute the net effect per matchup before
+  choosing step sizes.
+- **Two-round signal policy.** Single arena runs re-roll by ~±10% EHP
+  margin; a margin inside ±20% counts as converged for v1. Only act on
+  signals that persist across two rounds.
+- **Arena geometry is part of the fixture.** Lane width/height changes
+  the results (full engagement vs. fleets slipping past); margins are
+  only comparable within the same geometry.
+- **Accept mechanical texture.** Not every deviation is a bug: a margin
+  that survives a stat change is mechanical (usually range/kiting under
+  the orbit AI) and may be desirable doctrine texture. Document the
+  acceptance in `targets.md` instead of chasing it.
+- **Range is the strongest stat** under the orbit AI — free approach
+  fire. Price range modifiers conservatively; station dominance is
+  controlled via range, not HP.
+
+## Tools
+
+- `tools/threat_report.py` — item threats, module contributions,
+  hull/fitted ship threats, producer:consumer ratios, belt feasibility;
+  reads the real configs. The design reference for threat semantics.
+- `tools/verify_recipes.py` — recipe tree closure, visuals coverage,
+  orphans, reprocessing-only items.
+- `tools/verify_layouts.py` — module footprint gating matrix per hull.
+- **Balancing tool** (`balancing` target) — parallel arena simulation of
+  `bin/balancing/data/balancing.toml`; logs winner, surviving counts,
+  team EHP %, and fight duration per arena. The suite covers: class
+  mirrors (expect near-mutual annihilation, symmetric winners),
+  equal-threat cross-tier matchups (expect near-draws — power-per-threat
+  made empirical), a 2:1 decisiveness check, doctrine matchups
+  (armored-vs-glass, repair-escort), and station assault.
+
+## Checklist for the next balancing round
+
+1. Pull; run `verify_recipes.py`, `verify_layouts.py`,
+   `threat_report.py`; compare against the tables in `derived.md`.
+2. If recipes/materials changed: re-check fitted threats vs. the ladder
+   in `targets.md`; update arena suite ship counts if fitted values
+   moved.
+3. Run the arena suite; read EHP margins and durations against the
+   expectations noted in `balancing.toml` and the anchors.
+4. Apply changes per the tuning discipline (two-round signals only);
+   record the round and its knob changes in `history.md`.
+5. Update `derived.md` where values moved; if an anchor moved, update
+   `targets.md` and state why.
+6. Commit and push (the review workflow reads the remote).

docs/balancing/rules.md

@@ -0,0 +1,333 @@
+# Balancing & Progression Rules
+
+Rules and principles that govern the production tree, progression pacing,
+and balancing. This document contains **rules only** — the chosen base
+numbers live in `targets.md`, everything derived from them in
+`derived.md`, and the concrete content in the config files and
+`../content_design.md`. All of those must follow the rules stated here.
+
+## Player-experience goals
+
+What each phase of a run should feel like:
+
+- **Early:** learning belts and ratios with forgiving chains. The building
+  block economy is the main constraint; the player bootstraps a
+  self-sustaining factory from the starting stock.
+- **Mid:** deeper chains, the first real ratio puzzles, and the first
+  meaningful drop decisions (which schematic, when to push).
+- **Late:** combat feeds the factory — capital production requires salvage.
+  Progress means extending and refactoring the existing factory, not
+  rebuilding it. Strange ratios are deliberate optimization puzzles.
+
+Overarching: an experienced player gains efficiency through **knowledge** —
+layout foresight, understanding chains, exploiting shortcut recipes — never
+through hidden mechanics. An inexperienced setup should not cost much more
+than an experienced one; experience pays off in how easily the factory
+adapts later (see Refactorability).
+
+## Resource phases
+
+- A run has exactly **four base inputs**:
+  1. Two mined resources available from the start, minable on **every**
+     asteroid tile.
+  2. A third mined resource unlocked mid-game, minable **only on deposit
+     patches** found in expansion territory (see Resource deposits).
+  3. A fourth input unlocked late-game, obtainable **only** from
+     reprocessing salvaged scrap.
+- The fourth input is the core loop hook: capital ship production requires
+  fighting (salvaging and reprocessing), not just mining.
+- Every gating has a fictional reason (concrete fiction in
+  `../content_design.md`): the asteroid is a metal-rich body, so its bulk
+  rock is minable anywhere; the mid resource sits in rare pockets; the
+  late input is battle-forged — created only in the violence of ship
+  destruction, which is why any wreck (including the player's own)
+  yields it and no foundry can make it.
+- The mid resource is **dual-gated**: schematics (knowledge, via drops)
+  and territory (deposits, via expansions). Tuning must guarantee the
+  deposit-bearing expansion is comfortably affordable by the time the
+  first mid-tier schematics drop, or those drops are dead picks.
+- There is no direct "resource unlock" mechanism. Miner recipes unlock
+  **implicitly** (REQ-LOCK-IMPLICIT) when some unlocked schematic's material
+  chain reaches that resource. Resource pacing is therefore controlled
+  through the `unlock_at_station_level` values of ships, modules, and
+  assembler recipe schematics — and the content must guarantee that the
+  chains actually connect (a mid-game schematic must require an item whose
+  chain reaches the mid resource, or it never unlocks).
+
+### Resource deposits
+
+- **Rule: freedom first, geography later.** The starting resources are
+  minable everywhere, so the player has full layout freedom while
+  learning. Later mined resources are bound to deposit patches — fixed
+  geography as a layout puzzle, introduced once the player is competent.
+- **Rule: deposits exist only in expansion territory.** Expansions buy
+  space *and* access to resource tiers — the second leg of the growth
+  curve (see Building block economy).
+- **Rule: patch area is the throughput cap.** Deposits never deplete but
+  are finite in area; the number of deposit tiles caps how many miners
+  the chain supports. Buying deeper expansions raises the throughput
+  ceiling of high-tier chains.
+- **Rule: no empty expansions.** Deposit content per expansion is
+  deterministic and config-defined; only the placement within the new
+  columns is randomized. Buying an expansion never rolls "nothing".
+- **Rule: mining is binary.** A miner whose footprint overlaps at least
+  one deposit tile of a resource can select that resource's recipe; no
+  partial-coverage rate scaling.
+- Deposits arrive at the periphery (expansions add columns on the left),
+  so each new chain starts in fresh space — supporting the
+  refactorability property — and high-tier chains have the longest belt
+  runs to the shipyards, escalating the logistics puzzle with tier.
+
+## Production tree rules
+
+### Structure
+
+- **Each phase transition adds exactly one new base input chain.** A base
+  input is a bottom-level resource entering the factory from outside — a
+  mined resource or the scrap-only input. The early game starts with two
+  ores as the baseline; the transition to mid adds one (the deposit-bound
+  mid resource), the transition to late adds one (the scrap-only input).
+  No transition ever introduces more than one unfamiliar bottom-level
+  chain, so the factory grows in one direction at a time.
+- **Intermediates are generic shared parts.** Keep the item count low —
+  modules and hulls of a tier draw from a shared pool of that tier's and
+  lower tiers' intermediates rather than each having bespoke inputs.
+- **Thematic naming over thematic items.** Inputs should be plausible for
+  what the recipe produces (crystals for lasers, heat sinks for bigger
+  lasers). Achieve this through naming and chain membership, not by adding
+  item types: rename a generic part, don't add a parallel one.
+
+### Ratios
+
+- **Ratio "niceness" degrades with tier.** The producer:consumer ratios
+  needed for 100% throughput follow a curve:
+  - Tier 1 (ore → basic material): trivially nice (e.g. 1:1 or 1:2
+    miner:smelter).
+  - Tier 2: slightly complex but still clean (e.g. 2:3).
+  - Higher tiers: increasingly strange ratios, as deliberate optimization
+    puzzles.
+- Exceptions in both directions are allowed when there is a reason — a
+  clean late chain as a breather, an odd early chain as a teaser — but the
+  curve is the default.
+
+### Shortcut recipes
+
+- Some strange chains get a **shortcut recipe**: an explicitly unlockable
+  assembler recipe schematic (`unlock_at_station_level ≥ 0`, drop-only per
+  REQ-LOCK-EXPLICIT) that skips a step (e.g. t1 → t3 directly) and yields
+  nice ratios for a chain whose base path is strange.
+- **Not every strange chain gets a shortcut.** Some strangeness is
+  permanent; the absence of a fix is a valid design choice.
+- **Shortcuts drop only for known chains.** A shortcut recipe enters the
+  drop pool only when both its input items and its output item are
+  already unlocked (in addition to the station level check). The player
+  is never offered a shortcut for a chain they have not built yet. The
+  output-item half of this check already exists in
+  REQ-DEF-SCHEMATIC-DROP; the input half is an open action item (see
+  `README.md`).
+- **Shortcuts are pure rewards, never balance factors.** An item's threat
+  value is the *maximum* across its producing recipes (REQ-THREAT-ITEM), so
+  unlocking a cheaper recipe does not lower the item's threat accounting —
+  the player gains real factory efficiency without their ships being
+  valued cheaper and without enemy wave budgets shifting. Consequently:
+  **balance every chain around its base (expensive) path**; the shortcut's
+  savings define the size of the reward.
+
+### Refactorability
+
+- **Rule (the property):** unlocking the next tier or size of a thing must
+  be a *local edit* of the existing production line — adding assemblers
+  and belts, or replacing a machine or two in place — never a rebuild of
+  the line.
+- **What this buys the player:** foresight pays off in space, not blocks.
+  An experienced player leaves a little slack in the middle of a line,
+  knowing the next size or tier upgrade means tearing out one assembler
+  and a few belts there and inserting the new step — plus maybe swapping
+  a recipe or two elsewhere — while the rest of the line keeps running
+  untouched.
+- **Default technique:** the bigger version introduces one new intermediate
+  that is produced from a subset of the smaller version's inputs (possibly
+  plus one additional low-tier material), and otherwise reuses the smaller
+  version's inputs. Existing lines keep running and feed the new
+  intermediate's assemblers.
+- The property is the rule; the technique is only the default. It may be
+  broken where it fights thematic plausibility, as long as the property
+  still holds.
+
+## Cost archetypes
+
+Every item has two cost knobs: **material quantity** and **cycle time**.
+Both feed the threat value identically (threat = recursive
+production-seconds, REQ-MOD-THREAT), so the split between them does not
+change what an item is *worth* — it changes what kind of **factory
+pressure** it creates:
+
+- **Material-heavy, fast** (e.g. armor plates): simple items; stress belt
+  throughput, splitter logistics, and miner/smelter counts.
+- **Time-heavy, lean** (e.g. shield modules): technically complex items;
+  few inputs — possibly higher-tier ones — but long cycles; stress
+  assembler counts and parallelization.
+
+**Rule:** each module family commits to a clear archetype, so factories
+supporting different fleet doctrines feel structurally different to build.
+
+## Threat model (balancing backbone)
+
+- Threat cost = total recursive production-seconds (REQ-MOD-THREAT). One
+  factory-second equals one threat; player output and enemy wave budgets
+  are denominated in the same currency.
+- **Rule: combat power per threat is roughly constant** across all ships,
+  modules, and tiers. Higher tiers are better per *ship* and per *module
+  slot*, not per invested factory-second — their advantage is
+  concentration (fewer, bigger things; slot geometry per
+  `../content_design.md`) and qualitative capabilities, not a better
+  exchange rate. Deviations from this rule are deliberate and documented.
+- **Difficulty race:** the enemy threat rate (`threat_rate_formula`) is
+  tuned against the factory output (threat/s) achievable by a competent
+  player — slightly below it early, crossing above it eventually. The game
+  is endless; enemy scaling must ultimately outpace any factory, and
+  player skill shifts *when*, not *whether*.
+- **All time scaling lives in the threat rate** — waves get bigger, ships
+  of a given schematic never get individually stronger. There is no ship
+  level dimension: stat formulas are plain values, and per-ship level
+  scaling does not exist. Push scaling on enemy defence stations is the
+  separate, player-triggered difficulty axis and keeps its level formulas.
+
+## Unlock & drop pacing
+
+- **Starting set rule:** the schematics unlocked at game start
+  (`unlock_at_station_level = -1`) must be exactly enough to reach the
+  first push unaided — a functioning block loop, small hulls, a basic
+  weapon, and the salvage loop. Nothing more.
+- The `unlock_at_station_level` ladder mirrors the resource phases:
+  mid-tier hulls/modules/recipes at low station levels, capital content at
+  higher levels. A schematic must not become available before the chains
+  its materials need can be unlocked alongside it.
+- **Schematics can require other schematics.** Beyond the station-level
+  gate, a schematic (ship, module, or assembler recipe) may list
+  prerequisite schematics (`unlock_requires`, REQ-LOCK-PREREQ) that must
+  already be unlocked before it enters the drop pool — e.g. the medium
+  gun requires the small gun; a future Mk2 requires its base version.
+  Station level gates the earliest *when*; prerequisites gate the
+  *order*, keeping drop offers coherent with what the player already
+  owns.
+- **No duplicate drops.** Ship and module schematics leave the drop pool
+  once owned, exactly as assembler recipe schematics already do. There are
+  no schematic level-ups; player power grows through unlock breadth and
+  factory scale only, which keeps power-per-threat exact on both sides.
+  The pool therefore shrinks over a run and late pushes increasingly offer
+  artifacts — intended: the late game is a race for the win condition.
+  Per-item progression may return later as Mk2 upgrade recipes (see Future
+  work), never as free level-ups.
+- **Artifacts trade power for progress.** Artifact options compete with
+  schematic picks in the same choice dialog; the artifact chance must be
+  tuned so that taking one is a real decision (giving up an unlock), not
+  automatic in either direction.
+
+## Scrap & reprocessing economy
+
+- Scrap is the bridge from combat back into the factory, with two sinks:
+  **smelting** (same basic materials as ore — the safe, boring option) and
+  **reprocessing** (probabilistic higher intermediates, including the
+  late-game input — the gamble that eventually becomes mandatory).
+- The reprocessing output pool renormalizes over implicitly unlocked items
+  (REQ-LOCK-REPROCESSING-POOL), so its output quality improves
+  automatically as the run progresses. **Rule:** weights are authored for
+  the *fully unlocked* pool state; early-game behavior falls out of
+  renormalization for free and needs no separate staging.
+- **Rule: ship scrap drops are derived, never authored.** A destroyed ship
+  drops `threat cost × scrap_per_threat` (a `world.toml` key), with the
+  threat cost computed from its actual hull plus installed modules
+  (REQ-MOD-THREAT) — a kitted-out ship drops more scrap than a bare hull
+  automatically. `ships.toml` carries no scrap value. Defence stations are
+  the exception: they keep authored `scrap_drop_formula`s, because pushing
+  rewards are tuned independently of ship production costs.
+- Consequence: the threat value of scrap is the constant
+  `1 / scrap_per_threat` (REQ-THREAT-SCRAP). The former min-`scrap_drop`
+  schematic derivation and its potential circularity are gone.
+- **Rule:** the late-game input's income rate meaningfully gates capital
+  production — unlocking a capital hull must not mean spamming it; the
+  input trickles in slowly enough that every capital ship is a noticeable
+  investment. The tuning target is relative, not absolute: assume a
+  reference player who destroys and salvages roughly the threat the game
+  spawns ("fighting at parity"), and tune `scrap_per_threat`, the
+  reprocessing weights, and capital material costs so that this player
+  affords roughly N capital ships per boss cycle. An absolute income rate
+  would be meaningless (income depends entirely on how much the player
+  fights) and would not self-scale; per boss cycle, the target tracks the
+  threat rate as it steps up.
+
+## Building block economy
+
+- Building blocks are the only global currency and the early game's
+  central constraint. The early game is a bootstrap problem: convert the
+  starting stock into a self-sustaining block loop before the first waves
+  bite.
+- **Rule:** the starting stock suffices for a minimal block loop plus the
+  first shipyard — with a little slack for beginner mistakes, but not
+  enough to skip the loop entirely.
+- **Rule: the growth curve lives here.** A saturated building produces
+  exactly 1 threat/s, so the player's output curve *is* their
+  building-count curve — shaping growth over a run means shaping the
+  block and space economy, there is nowhere else it can live. Intended
+  shape: exponential bootstrap (block-limited) → ramp
+  (expansion-limited) → asymptotic squeeze as expansion costs outrun
+  income, racing the enemy threat rate throughout.
+- **Rule: escalating expansion costs.** Expansion cost is a formula of
+  the number of expansions already purchased, rising steeply enough that
+  expansions eventually outrun any block income. The starting asteroid
+  is deliberately small — filled within the first boss cycle or two, so
+  the early exponential burst is a satisfying ramp, not a balance hole —
+  and from then on the output curve is the expansion curve. Blocks keep
+  a meaningful sink for the entire run, and "grow vs. army" stays a live
+  decision at every moment.
+- **Rule: designed doubling time.** Block production is a positive
+  feedback loop (blocks buy assemblers, assemblers make blocks); its
+  time constant is a designed quantity, never an accident of quantity
+  choice. The block chain's depth and the per-building costs are tuned
+  against a stated target of the form: "a factory spending X% of its
+  capacity on blocks doubles in ~T minutes."
+- **Rule: growth is limited by economy, never by waiting.** Construction
+  times stay short; the serial build queue must not be used as a growth
+  brake. Waiting for placed buildings to become operational — especially
+  at the start of a run — is frustration, not gameplay. All growth
+  limiting comes from block income and expansion pricing.
+- Note: block income has a structural ceiling — blocks enter the stock
+  through the HQ's single belt port, so income is capped at belt
+  throughput regardless of assembler count. Per-building costs should be
+  high enough that this cap can bind late-game (see the condensed-block
+  idea under Future work).
+
+## Numeric guardrails
+
+Constraints that every recipe must respect, independent of tuning:
+
+- **Belt throughput:** belt speed and per-tile capacity cap how fast a
+  single belt can feed an input. A recipe whose per-cycle inputs cannot be
+  sustained by one belt per input at 100% duty cycle is a *deliberate*
+  design (forcing parallel belts/splitters as part of a high-tier puzzle)
+  — never an accident of quantity choice.
+- **Buffer burstiness:** input buffers hold 2× the per-cycle amount
+  (REQ-MAT-INPUT-BUFFER), so large per-cycle quantities create bursty belt
+  demand. Low tiers prefer small quantities with short cycles; big-batch
+  recipes are reserved for high tiers where burstiness is part of the
+  puzzle.
+- **Cycle times scale with tier** monotonically — a higher-tier item never
+  has a shorter total chain time than a lower-tier item of the same role.
+
+## Future work
+
+- **Condensed building blocks** — a drop-unlockable shortcut-style
+  recipe that packs several blocks' worth of value into one belt item,
+  relieving the HQ intake ceiling (see Building block economy) as a
+  late-game reward. The ceiling is the puzzle, the drop is the fix —
+  same philosophy as shortcut recipes.
+- **Mk2 upgrade recipes** — the deferred design for per-item progression,
+  to revisit once the config has stabilized. A duplicate-style drop
+  unlocks a distinct `*_mk2` item whose recipe consumes the Mk1 item plus
+  higher-tier parts. This preserves power-per-threat (the extra power is
+  paid in real production-seconds, since threat is recursive), satisfies
+  the refactorability rule (the Mk1 line keeps running and feeds one new
+  assembler), and keeps balancing one-dimensional (no level variable
+  anywhere). Enemy-side progression happens via `default_modules`
+  variants per era instead of a level formula.

docs/balancing/targets.md

@@ -0,0 +1,104 @@
+# Balancing Targets (base numbers)
+
+The root numbers of the balancing. Everything in `derived.md` is tuned to
+hit these; when rebalancing, **change these first and re-derive — never
+patch derived values directly**. The rules these numbers follow live in
+`rules.md`.
+
+All time targets are in **game time**. The player can pause and
+accelerate, so real session length differs; playtests measure both. The
+time unit is the boss cycle (`world.toml boss_countdown_seconds`, 300 s).
+Destroying a station set advances the boss countdown by
+`boss_advance_seconds` (60 s), so cycles run shorter than nominal when
+pushing actively — targets deliberately ignore that.
+
+## Run shape
+
+1. **Run length** — a winning run takes up to 2 hours of game time: win
+   around boss cycle 20–24. Losing runs end earlier.
+2. **Phase boundaries** — early = cycles 1–5 (iron/copper, small hulls),
+   mid = cycles 6–14 (quartz, medium hulls), late = cycles 15+
+   (voidsteel, capitals). Push cadence: first station set around cycle
+   2–3, roughly one per cycle from mid onward — so the destroyed set's
+   level ℓ is reached around cycle ℓ+2.
+3. **Factory size curve** — producing buildings over time; when
+   saturated, output threat/s equals this count, so this curve IS the
+   player power curve: ~25 when the starting asteroid is full (end of
+   cycle 2), ~60 at the start of mid (cycle 6), ~120 at the start of
+   late (cycle 15), ~150 near the win. `threat_rate_formula` must remain
+   a fraction of this curve; buildings plus belts must physically fit
+   the asteroid plus affordable expansions.
+4. **Threat-cost ladder** — total production-seconds per *fitted* hull
+   (including the typical/default module loadout): drone 10.5,
+   frigate 47, destroyer 99, cruiser 233.5, battlecruiser 354.5,
+   battleship 722.5, dreadnought 1491.5, carrier 1436.5. Every
+   production chain must sum to its ladder value. (The original strawman
+   was 10/40/80/200/350/700/1500; the small end runs ~10–20% hot because
+   fixed chain overhead dominates small hulls — accepted, and the
+   achieved values adopted as the ladder. The ~×2-per-class curve shape
+   is the invariant.)
+5. **Fleet size** — swarm-leaning: ~25 player combat ships as the
+   standing mid-game fleet. Standing fleet = build cadence (4) × average
+   ship lifetime, so this target drives time-to-kill and therefore all
+   combat stat magnitudes.
+6. **Block economy roots** — bootstrap complete (starting asteroid full)
+   by the end of cycle 2; a factory spending ~30% of its capacity on
+   blocks doubles in ~4 minutes early game; one expansion affordable per
+   cycle at ~1/3 of block income mid-game, decelerating to one per 2–3
+   cycles late as escalating costs outrun income.
+
+## Combat anchors
+
+All combat stats derive from these; per-hull HP additionally carries
+empirical trims from arena rounds (values in `derived.md`).
+
+- **Weapon DPS per threat pays a concentration tax that grows with gun
+  size**: small ≈ 0.62, medium ≈ 0.48, large ≈ 0.41 DPS per threat of
+  weapon contribution, compensated by the range ladder 50/70/100 m.
+  Rationale: concentration itself (focus fire, no DPS loss to attrition,
+  range) is worth paying for — with a flat curve, concentrated fleets
+  win equal-threat fights outright (arena round 1).
+- **Hull HP = 15 per threat of hull contribution** as the prior; per-hull
+  HP is the empirical trim knob (guns are shared across hulls, hull HP
+  moves exactly one matchup). The arena consistently prices capitals as
+  *tanks with taxed guns* — capital hulls sit well above the prior.
+- **Armor HP ≈ 37 per threat** — a strong premium over hull HP because
+  armor is pure HP with no capability, and fights snowball: killing
+  removes enemy DPS, surviving merely delays — HP must be cheaper than
+  DPS.
+- **Repair ≈ 0.7 HP/s per threat** — in-combat sustain effectively
+  removes enemy DPS and must be priced like DPS, not like HP.
+- **TTK / fight duration**: parity fights in the 30–60 s band at
+  mid-game scale; capital mirrors ~90 s deliberately; the extreme
+  tank-vs-chip-damage matchup (dreadnought vs destroyer swarm, ~3.5 min)
+  is an accepted outlier.
+- **Mobility is monotone in size** — the smallest hulls are the fastest
+  and nimblest. Sensor ranges (150→350 m) always exceed weapon ranges.
+- **Weapon modifiers are capital economy**: a ×1.2 damage modifier at
+  ~22.5 threat beats adding a gun once a ship carries more than ~68
+  threat of weapons — modifiers pay off on gun-heavy big hulls, waste on
+  small ones. Range modifiers are the strongest and are priced/kept
+  small (×1.3): range is the dominant stat under the orbit AI (free
+  approach fire).
+- **Stations**: a fresh player station holds one early parity wave
+  unaided; the enemy station at level 0 matches the player station
+  exactly and scales per push level. Station range is the dominance
+  lever, not HP (at 4× a small gun's range, two stations annihilated a
+  3× threat swarm through approach fire alone).
+- **Accepted imbalances**: the carrier loses its equal-threat fights
+  until the drone-launching capability exists (the hangar is dead
+  threat) — fix by implementing drones, not stats. A pure smallest-ship
+  fleet modestly loses (~15–25%) to a range-fitted capital — desirable
+  doctrine texture; the fair anti-capital answer is the mixed fleet.
+
+## Pacing anchors
+
+- **Starting set** is the rule-minimum: drone, frigate, small gun,
+  salvager (plus the explicitly unlocked building-block recipe).
+- **Threat rate shape**: below the player's achievable military output
+  (≈ half the factory curve) early, crossing at the late boundary
+  (~cycle 15), overwhelming by ~cycle 24.
+- **Winning = five real decisions**: `artifact_win_count` is set so that
+  across a winning run's ~15–18 pushes (~7 cumulative artifact offers at
+  the current chance formula), the player must choose the artifact over
+  a schematic about five times.

docs/content_design.md

@@ -1,9 +1,10 @@
-# Content Design — Ships & Modules
+# Content Design — Ships, Modules & Production Tree
 
-First real-content iterations (June 2026). Pass 1 defined ship hull grids and
-module surface masks; pass 2 defined the production tree (recipes). Stats and
-threat costs in the config files are still placeholders for the balancing
-pass.
+The designed game content: hull layout grids, module footprints and the
+gating between them, and the production tree (items, chains, fiction).
+All numbers — quantities, durations, threat values, stats, unlock levels
+— live in the config files and are documented with their derivations in
+`docs/balancing/` (see `balancing/README.md` for the index).
 
 ## Design principle: footprint gating
 
@@ -17,12 +18,12 @@ and makes them trivially moddable through the config files alone.
 
 | Footprint | Modules | Smallest hull that fits it |
 |-----------|---------|----------------------------|
-| 1x1 | laser_cannon_s, salvager, repair_tool | drone |
+| 1x1 | railgun_s, salvager, repair_tool | drone |
 | 1x2 | maneuvering_thrusters, sensor_booster, armor_plates | frigate |
 | 1x3 | afterburner | frigate (eats most of it) |
 | L-shape (3 cells) | weapon_stabilizer, weapon_primer, weapon_upgrade | frigate |
-| 2x2 | laser_cannon_m, drone_bay | cruiser |
-| 3x3 | laser_cannon_l | battleship |
+| 2x2 | railgun_m, drone_bay | cruiser |
+| 3x3 | railgun_l | battleship |
 | 2x6 | drone_hangar | carrier (only) |
 
 ### Hull grids
@@ -131,64 +132,163 @@ drone hangar — carrier 1.
 
 ## Production tree
 
-Design principle: each game phase adds exactly one new base input chain, so
-factory complexity ramps alongside ship size.
+Designed against the rules in `docs/balancing/rules.md` (ratio curve,
+cost ladder, cost archetypes, refactorability). Quantities, durations,
+and threat values live in `docs/balancing/derived.md`.
 
-| Phase | New input | How acquired | Unlocks |
-|-------|-----------|--------------|---------|
-| early | iron_ore, copper_ore | mined | drone, frigate, destroyer; small guns and basic supports |
-| mid | titanium_ore | mined (3x slower than iron) | cruiser, battlecruiser; m guns, drone bay, weapon modifiers |
-| late | advanced_alloy | ONLY from reprocessing salvaged scrap | battleship, dreadnought, carrier; l guns, drone hangar |
+### Base inputs (4) and fiction
 
-The advanced_alloy gate is the core loop hook: capital ship production
-requires fighting (salvaging scrap from kills and reprocessing it), not just
-mining. The reprocessing plant turns 5 scrap into iron/copper/titanium ingots
-or advanced_alloy probabilistically.
+- **iron_ore, copper_ore** — from the start, minable on every asteroid
+  tile. Fiction: the asteroid is an M-type (metal) body — its bulk rock
+  *is* ore, which is why the shipyard operation was built here at all.
+- **quartz** — mid-game, minable only on geode deposit patches in
+  expansion territory (see the Resource deposits rules in
+  `docs/balancing/rules.md`; the deposit mechanic itself is an open
+  action item — until it lands, quartz mines anywhere). Fiction:
+  ordinary silicate dust is everywhere and worthless; chips and optics
+  need rare, pocket-bound optical-grade crystal.
+- **voidsteel** — late-game, obtained only by reprocessing scrap.
+  Fiction: battle-forged — formed when weapon plasma anneals hull metal
+  in the violence of ship destruction. Any wreck yields it, including the
+  player's own; no foundry can replicate it.
+- **titanium was dropped** (v1 tree). Its hull-gating role moved to
+  quartz-era control systems ("you can smelt all the steel you want, but
+  you cannot steer a battlecruiser without electronics") plus the
+  hardened-steel quality step (a deliberately long-running, time-heavy
+  recipe) — explicitly not sheer steel quantity alone.
 
-Intermediate components, by tier:
+### Material palette (fingerprints per family)
 
-- **Tier 2 (early):** copper_wire (copper), steel_plate (iron), circuit_board
-  (iron + wire), building_block (iron).
-- **Tier 3 (mid):** mechanical_parts (steel + iron), targeting_unit (circuits
-  + wire), drive_unit (steel + mechanical_parts + circuit), titanium_frame
-  (titanium + steel).
-- **Tier 4 (late):** reinforced_plating (steel + advanced_alloy),
-  capital_core (targeting_unit + drive_unit + 2 advanced_alloy).
+- **iron/steel** — structure.
+- **copper** — conduction and heat: wiring, coils, heat sinks.
+- **silicon family** (all derived from quartz): silicon (logic,
+  sensors), ceramics (heat shielding, insulators); glass/optics are cut
+  from v1 — their only consumers would be lasers, which are deferred.
+- **voidsteel** — capital-tier structure and exotics.
+- Deliberately skipped: carbon (mostly redundant with copper/ceramics),
+  plastics (drags in Factorio-style chemical chains; ceramics read more
+  sci-fi anyway), volatiles/ice (materials are build costs only — no
+  consumption mechanic to justify fuel).
 
-Hulls and modules consume intermediates of their tier: early items are built
-from tier-2 parts, midgame items require tier-3 parts (deeper chains, more
-assemblers), capital items require tier-4 parts (and therefore combat). Hull
-items are named `<ship>_hull`; module items `<module>_module`. Every item has
-an `[items.*]` entry in visuals.toml; hull item outlines match the ship's
-fleet color from `[ships.*]`.
+### Weapons
 
-Consistency is checked by `tools/verify_recipes.py` — re-run it after editing
-recipes, ship/module materials, or visuals:
+- All v1 weapons are **railguns** (`railgun_s/m/l`, renamed from the
+  laser placeholders; footprints and the gating matrix unchanged).
+  Implementation is instant damage application with no projectile and no
+  ammunition — the beam visual reads as a tracer round. Materials: iron
+  slugs, copper coils, steel rails — the starting-metal fingerprint.
+- **Lasers are reserved for later** as a genuinely distinct weapon type
+  (e.g. once projectile/ammunition mechanics exist for other families),
+  arriving with quartz optics. More weapon types are planned; railguns
+  are simply the baseline tech that ships with v1.
+- `drone_bay` and `drone_hangar` are footprint-only placeholders: the
+  drone-launching capability does not exist in the simulation yet, so
+  they define no capability section. The carrier is deliberately weak
+  until that capability lands (see the accepted imbalances in
+  `docs/balancing/targets.md`).
+
+### Tree structure
+
+Input lists only — quantities, durations, and per-item threat values are
+in `docs/balancing/derived.md` and the configs.
+
+**Mined (miner):** `iron_ore`, `copper_ore` (every tile), `quartz`
+(geode deposits in expansion territory).
+
+**Smelted (smelter — exactly one recipe per input item):**
+
+| output | input | ratio class |
+|---|---|---|
+| iron_ingot | iron_ore | nice (1:1) |
+| copper_ingot | copper_ore | nice |
+| silicon | quartz | mid entry |
+| iron_ingot | scrap | the safe, boring scrap sink |
+
+**Reprocessing pool (scrap):** `iron_ingot`, `copper_ingot`, `silicon`,
+`voidsteel` — the only source of voidsteel. Weights authored for the
+fully unlocked pool state.
+
+**Tier 2 — early intermediates (clean ratios, ~2:3):**
+
+| item | inputs | role |
+|---|---|---|
+| steel_plate | iron_ingot | structure backbone, highest volume |
+| copper_wire | copper_ingot | conductors |
+| copper_coil | copper_wire | electromagnets: railguns, thrusters |
+| building_block | steel_plate | depth-3 chain = the doubling-time knob |
+
+**Tier 3 — mid intermediates (strange ratios begin, need quartz):**
+
+| item | inputs | role |
+|---|---|---|
+| control_chip | silicon + copper_wire | electronics gate for m+ hulls |
+| capacitor_bank | copper_coil + silicon | power for railgun m/l |
+| hardened_steel | steel_plate (long cycle) | quality gate for m+ hulls; time-heavy |
+| ceramic_plate | quartz | heat shielding: drives, l guns, capitals |
+| drive_unit | steel_plate + copper_coil + control_chip | propulsion for m+ hulls |
+
+**Tier 4 — late intermediates (need voidsteel):**
+
+| item | inputs | role |
+|---|---|---|
+| voidsteel_plate | voidsteel + hardened_steel | capital structure |
+| capital_core | voidsteel + capacitor_bank + control_chip | capital heart |
+
+**Hull items** (`<ship>_hull`, assembler-made; the shipyard consumes the
+hull item plus module materials). The m+ hull gate is **both**
+hardened_steel (quality steel, the time-heavy step) *and* control_chip
+(electronics):
+
+| hull | inputs |
+|---|---|
+| drone_hull | iron_ingot |
+| frigate_hull | steel_plate + copper_wire |
+| destroyer_hull | steel_plate + copper_coil |
+| cruiser_hull | hardened_steel + control_chip |
+| battlecruiser_hull | hardened_steel + control_chip + drive_unit |
+| battleship_hull | voidsteel_plate + drive_unit + control_chip |
+| dreadnought_hull | voidsteel_plate + capital_core + drive_unit |
+| carrier_hull | voidsteel_plate + capital_core + drive_unit |
+
+**Module items** (`<module>_module`, assembler-made prefabs — kept as
+items so shipyard belt inputs stay simple and module production can be
+stockpiled):
+
+| module | inputs | archetype |
+|---|---|---|
+| railgun_s | copper_coil | lean |
+| salvager | steel_plate + copper_wire | balanced |
+| repair_tool | steel_plate + copper_wire | balanced |
+| armor_plates | steel_plate (many) | material-heavy, fast |
+| maneuvering_thrusters | steel_plate + copper_coil | balanced |
+| sensor_booster | copper_wire + copper_coil | lean (an antenna, no chip) |
+| afterburner | copper_coil + steel_plate | balanced |
+| weapon_stabilizer | steel_plate + copper_coil | balanced |
+| weapon_primer | capacitor_bank + copper_coil | mid; time-heavy |
+| weapon_upgrade | control_chip + copper_coil | mid; time-heavy |
+| railgun_m | capacitor_bank + steel_plate + copper_coil | mid |
+| drone_bay | control_chip + steel_plate + copper_coil | mid |
+| railgun_l | capacitor_bank + hardened_steel + ceramic_plate | late |
+| drone_hangar | voidsteel_plate + control_chip + drive_unit | late (carrier only) |
+
+**Refactorability check** (the default technique holds): railgun_s → m
+introduces capacitor_bank, built from a subset of the small gun's inputs
+(copper_coil) plus the new base resource (silicon); the m gun otherwise
+reuses the small gun's inputs. Hulls likewise: the cruiser adds
+hardening (fed by the existing steel line) and chips (fed by the new
+quartz territory) without touching the iron/copper core.
+
+**Shortcut recipes** (drop-only assembler schematics; not every strange
+chain gets one): `iron_ore → steel_plate` (skips the ingot step on the
+highest-volume chain), `quartz → control_chip` (skips silicon),
+`iron_ingot → hardened_steel` (a nicer-ratio route past the deliberately
+awkward hardening step).
+
+Consistency is checked by `tools/verify_recipes.py` — re-run it after
+editing recipes, ship/module materials, or visuals:
 
     python dota_factory/tools/verify_recipes.py
 
 It verifies every consumed item has a producer, every item has a visuals
-entry, flags orphaned items, and prints which items are reprocessing-only
-(currently exactly advanced_alloy).
-
-## Deliberate placeholders / open questions for later passes
-
-- All new hulls have `threat.cost_formula = "0"` so enemy waves do not spawn
-  them yet (WaveSystem treats any ship with positive threat cost as wave-
-  eligible, regardless of unlock level). The balancing pass should set real
-  threat costs together with `default_modules` loadouts so waves spawn them
-  armed.
-- All new hulls and all assembler recipes are `unlock_at_station_level = -1`
-  (available from the start) to make testing easy; the balancing pass should
-  stagger these so mid/lategame recipes drop as schematics from enemy defence
-  stations.
-- Recipe quantities and durations are a first guess, deliberately roughly
-  tiered (capital hulls ~60 s, drones 4 s); the balancing pass tunes them.
-- `drone_bay` and `drone_hangar` are footprint-only placeholders: the drone
-  launching capability does not exist in the simulation yet, so they define
-  no capability section.
-- Renames in this pass: `laser_cannon_xs` → `laser_cannon_s` (the old 2x2
-  `laser_cannon_s` became `laser_cannon_m`), `armor_plate` → `armor_plates`,
-  `manuvering_thrusters` → `maneuvering_thrusters` (typo fix). Test data
-  under `bin/test/data/config` intentionally still uses the old ids — it is
-  an independent fixture set.
+entry, flags orphaned items, and prints which items are
+reprocessing-only (currently exactly voidsteel).

docs/requirements.md

@@ -4,11 +4,11 @@
 
 Config files use the TOML format. The following config files drive game parameters:
 
-- **world.toml** — world dimensions, region widths, expansion amounts, building refund percentage, wave timing, boss wave timing, belt speed, starting building blocks, departure interval, ship orbit factor, rally orbit radius, scrap-per-threat conversion, combat target-selection parameters (target score formula, overclaim penalty formula, target hysteresis), artifact chance formula, and artifact win count.
-- **buildings.toml** — building block cost and construction time per building type.
-- **recipes.toml** — crafting recipes: inputs, outputs, quantities, durations, and reprocessing plant probabilities. Assembler recipe entries may optionally define `unlock_at_station_level` (integer): -1 means the recipe is explicitly unlocked at game start; a value ≥ 0 means the recipe starts locked and a schematic for it can be awarded via defence station destruction (see REQ-LOCK-EXPLICIT, REQ-DEF-SCHEMATIC-DROP).
-- **ships.toml** — per schematic: a human-readable display name (used in the UI), hull stats (HP, max linear speed, sensor range, main acceleration, maneuvering acceleration, angular acceleration, max rotation speed) as plain values, required build materials, the station level at which the schematic becomes available for unlock (`unlock_at_station_level`; -1 means the player starts with the schematic already unlocked), a layout grid defining the ship's module slots, and a `default_modules` list used for enemy wave ships (see REQ-WAV-DEFAULT-MODULES).
-- **modules.toml** — per module type: id, surface mask, materials list, production time, fill color, glyph, the station level at which the schematic becomes available for unlock (`unlock_at_station_level`; -1 means the player starts with the module schematic already unlocked), and an optional capability section and/or stat modifier formulas. A module with a capability section (`[module.weapon]`, `[module.salvage]`, or `[module.repair]`) containing base stat formulas is a **capability module** that grants the ship a weapon, salvage bay, or repair tool per instance (see REQ-MOD-CONFIG for the full list of formulas per capability type). A module with only `added_*`/`multiplied_*` formulas is a **passive module** that modifies stats on the ship or on capability module instances (see REQ-MOD-STAT-CALC).
+- **world.toml** — world dimensions, region widths, expansion amounts, building refund percentage, wave timing, boss wave timing, belt speed, starting building blocks, departure interval, ship orbit factor, rally orbit radius, scrap-per-threat conversion, combat target-selection parameters (target score formula, overclaim penalty formula, target hysteresis), artifact chance formula, artifact win count, view pan speeds (slow and fast horizontal pan speed and pan ramp band width), and an optional building blocks tooltip string (shown as the header bar's building blocks stock hover tooltip, REQ-UI-BLOCKS-TOOLTIP; omitted when unset).
+- **buildings.toml** — building block cost and construction time per building type, plus an optional tooltip description string per building type (shown as the build button's hover tooltip, REQ-UI-BUILD-TOOLTIP; omitted when unset).
+- **recipes.toml** — crafting recipes: inputs, outputs, quantities, durations, and reprocessing plant probabilities. Assembler recipe entries may optionally define `unlock_at_station_level` (integer): -1 means the recipe is explicitly unlocked at game start; a value ≥ 0 means the recipe starts locked and a schematic for it can be awarded via defence station destruction (see REQ-LOCK-EXPLICIT, REQ-DEF-SCHEMATIC-DROP). An assembler recipe schematic entry may also define an optional `unlock_requires` list of prerequisite schematic ids (REQ-LOCK-PREREQ).
+- **ships.toml** — per schematic: a human-readable display name (used in the UI), hull stats (HP, max linear speed, sensor range, main acceleration, maneuvering acceleration, angular acceleration, max rotation speed) as plain values, required build materials, the station level at which the schematic becomes available for unlock (`unlock_at_station_level`; -1 means the player starts with the schematic already unlocked), an optional `unlock_requires` prerequisite list (REQ-LOCK-PREREQ), a layout grid defining the ship's module slots, and a `default_modules` list used for enemy wave ships (see REQ-WAV-DEFAULT-MODULES).
+- **modules.toml** — per module type: id, surface mask, materials list, production time, fill color, glyph, an optional tooltip description string (shown as the module selection button's hover tooltip, REQ-MOD-UI-MODULE-TOOLTIP; omitted when unset), the station level at which the schematic becomes available for unlock (`unlock_at_station_level`; -1 means the player starts with the module schematic already unlocked), an optional `unlock_requires` prerequisite list (REQ-LOCK-PREREQ), and an optional capability section and/or stat modifier formulas. A module with a capability section (`[module.weapon]`, `[module.salvage]`, or `[module.repair]`) containing base stat formulas is a **capability module** that grants the ship a weapon, salvage bay, or repair tool per instance (see REQ-MOD-CONFIG for the full list of formulas per capability type). A module with only `added_*`/`multiplied_*` formulas is a **passive module** that modifies stats on the ship or on capability module instances (see REQ-MOD-STAT-CALC).
 - **stations.toml** — HP, damage, range, fire rate, and scrap drop for player and enemy defence stations, defined as formulas of station level.
 - **visuals.toml** — rendering-only config (not game parameters): fill and outline colors and glyphs for every building type, item type, ship schematic, and station type; a distinct beam color per tool type (weapon, repair, salvage) and beam width; overlay and toast colors. Loaded by the UI at startup; the simulation does not read it.
 - **ship_layouts.toml** — named layout blueprints per ship type; written and read by the application to persist the layout blueprint panel (REQ-MOD-UI-BLUEPRINT-PANEL through REQ-MOD-UI-BLUEPRINT-FILE-LOAD). Not a game parameter file; the simulation does not read it.
@@ -68,7 +68,7 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 ## Game World
 
 - REQ-GW-COORDS: Tile coordinates are integer `(x, y)`. The origin `(0, 0)` is the first column of space — the tile immediately to the right of the asteroid's right edge at game start, at the top of the world. X grows right; Y grows down. All asteroid tiles have `x < 0`; asteroid left-expansions add tiles at increasingly negative X. The origin never shifts.
-- REQ-GW-TILE-SIZE: Tiles are square. The tile size in pixels is derived automatically so that the world height (in tiles) exactly fills the game world view's height in pixels. Items on belts are rendered at half-tile size; when multiple items occupy the same tile they are spaced quarter-tile apart along the direction of travel and overlap, rendered in ascending order of progress — the least-progressed item is drawn first (bottom) and the furthest-progressed item is drawn last (on top).
+- REQ-GW-TILE-SIZE: Tiles are square. The tile size in pixels is derived automatically so that the world height (in tiles) exactly fills the game world view's height in pixels. Items on belts are rendered at half-tile size; when multiple items occupy the same tile they are spaced quarter-tile apart along the direction of travel and overlap, rendered in ascending order of progress — the least-progressed item is drawn first (bottom) and the furthest-progressed item is drawn last (on top). Items emerging from a building's output port are rendered by these same rules on that port's output belt (REQ-MAT-OUTPUT-EMERGE).
 - REQ-GW-BELT-CAPACITY: Belt tiles and tunnel entry/exit tiles each hold up to four items simultaneously, queued one behind the other in the direction of travel. Splitter tiles hold up to four items: two unassigned items (progress < 0.5, not yet routed to an output) and one item per output slot (progress ≥ 0.5, committed to a specific output direction). Output-slot items are rendered on top of unassigned items; when both output slots are occupied, their rendering order follows the clockwise port order starting from East.
 - REQ-GW-BELT-SPEED: Items on belts move at `world.toml [world].belt_speed_tiles_per_second` tiles per second (default 2).
 - REQ-GW-HEIGHT: The world height (in tiles) is read from `world.toml [world].height_tiles`.
@@ -109,7 +109,15 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 - REQ-BLD-BELT-DRAG: For belts, the player can click and drag across multiple tiles to place a construction site on each tile in one gesture.
 - REQ-BLD-TUNNEL-AUTO-SWITCH: After the player successfully places a Tunnel Entry construction site, builder mode automatically switches to Tunnel Exit (and vice versa), preserving the current ghost rotation. This makes it easy to immediately place the paired end without manually selecting the complementary type.
 - REQ-BLD-DEMOLISH: The player can demolish a placed factory building. Demolition returns `world.toml [world].refund_percentage` percent of the original building block cost (default 75%) to the global stock. Exception: if the building is still in the construction queue (not yet fully built, including the one currently being constructed), it is removed from the queue and the **full** building block cost is refunded. The HQ and player defence stations cannot be demolished.
+- REQ-BLD-DEMOLISH-CLICK: While in demolish mode (REQ-UI-HOTKEYS, REQ-UI-DEMOLISH-BUTTON), left-clicking a placed factory building or construction site in the game world demolishes it, following the refund rules of REQ-BLD-DEMOLISH — the partial refund for built buildings and the full refund for still-queued construction sites. Clicking a building that cannot be demolished (the HQ or a player defence station, per REQ-BLD-DEMOLISH), or clicking empty world space, has no effect. Demolish mode stays active after a demolition so the player can demolish further buildings without re-entering the mode; it is exited via the Q toggle (REQ-UI-HOTKEYS) or the Demolish button (REQ-UI-DEMOLISH-BUTTON).
+- REQ-BLD-DEMOLISH-BOX: While in demolish mode (REQ-UI-HOTKEYS, REQ-UI-DEMOLISH-BUTTON), the player can click and drag a selection box in the game world. A selection rectangle is drawn while dragging, using the same box-drag gesture and coverage semantics as the multi-select box (REQ-UI-MULTI-SELECT). On mouse up, every placed factory building and construction site covered by the box is demolished, each following the refund rules of REQ-BLD-DEMOLISH — the partial refund for built buildings and the full refund for still-queued construction sites. Buildings that cannot be demolished (the HQ and player defence stations, per REQ-BLD-DEMOLISH) are excluded from the box demolition; ships and defence stations are never affected.
 - REQ-BLD-SITE-CONFIG: A construction site — a building that has been placed but is still queued or under construction (REQ-BLD-QUEUE) — can be selected and configured exactly like the equivalent operational building, before it finishes building. Whatever configuration the building type supports is available on the site: the recipe for a Miner or Assembler (REQ-UI-SELECT-BUTTON), the produced-ship schematic and its module layout for a Shipyard (REQ-UI-SELECT-BUTTON, REQ-MOD-UI-PREVIEW, REQ-MOD-UI-DIALOG), and the output filters for a Splitter (REQ-BLD-SPLITTER) — all set through the same Selected Building Panel controls (REQ-UI-CONFIG-INLINE). Only currently unlocked recipes and schematics are offered, exactly as for operational buildings (REQ-LOCK-UI-RECIPE, REQ-LOCK-UI-SCHEMATIC, REQ-LOCK-UI-SPLITTER). The configuration is stored on the construction site and carries over unchanged when construction completes, so the building becomes operational already configured. A construction site has no input/output buffers and runs no production cycle, so the buffer and production-progress portions of the panel (REQ-UI-SINGLE-SELECTION, REQ-UI-PRODUCTION-PROGRESS) are not shown for it; only its construction progress (REQ-UI-CONSTRUCTION-PROGRESS) and its configuration controls appear. (Blueprint placement already applies a stored recipe or schematic to a construction site on placement per REQ-UI-BLUEPRINT-PLACE; this requirement additionally lets the player set or change that configuration directly on an existing site.)
+- REQ-BLD-COPY-CONFIG: **Copy building settings (hold Shift).** While the Shift key is held, the player can copy one building's settings onto other buildings of the same type, so several identical machines can be set up without opening each one's panel. This gesture is available only in the default selection mode; while a builder, blueprint placement, or demolish mode is active it is disabled, so it never clashes with placement or demolition clicks.
+  - **Shift + right-click** a building copies its current settings into a temporary cache, along with the building's type. The settings copied are whatever that building type supports: the selected recipe (Miner, Assembler), the selected schematic together with its module layout (Shipyard), or the two output filters (Splitter, REQ-BLD-SPLITTER). Copying succeeds only when there is something to copy — a Miner or Assembler with a recipe selected, a Shipyard with a schematic selected, or any Splitter (whose output filters, even when empty/accept-all, always constitute valid settings). Shift + right-clicking a configurable building with nothing yet selected, a building type that has no settings at all (Smelter, Reprocessing Plant, Salvage Bay, belt/tunnel tiles, the HQ), or empty world space, has no effect and leaves any existing cache unchanged.
+  - **Shift + left-click** a building of the **same type** as the cached one applies the cached settings to it, exactly as if the player had made that selection through the selected building panel — with the same effects as a normal selection change (buffer clearing per REQ-MAT-INPUT-BUFFER and REQ-MAT-OUTPUT-BUFFER, and, for a Shipyard, in-progress cycle cancellation per REQ-BLD-SHIPYARD). This can be repeated on any number of same-type buildings while Shift stays held. Shift + left-clicking a building of a different type than the cached one, any building while the cache is empty, or empty world space, has no effect.
+  - Both operational buildings and construction sites take part as source and target (REQ-BLD-SITE-CONFIG); settings applied to a construction site carry over unchanged when it finishes building.
+  - **Releasing Shift clears the temporary cache.** It is never persisted and does not survive Shift being released; the next copy starts fresh.
+  - Because the cached settings were already valid on a same-type source building, they remain valid and available on the target (a selected recipe/schematic stays unlocked per REQ-LOCK-UI-RECIPE and REQ-LOCK-UI-SCHEMATIC; splitter filter item types stay unlocked per REQ-LOCK-UI-SPLITTER).
 
 ## Building Types
 
@@ -118,15 +126,15 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 - REQ-BLD-ASSEMBLER: **Assembler** (3×3): The player selects a recipe from the config-defined crafting tree. Produces the selected output item at the rate defined in the corresponding `recipes.toml [[recipe]]` entry with `building = "assembler"`. Only implicitly unlocked recipes are available for selection (REQ-LOCK-UI-RECIPE).
 - REQ-BLD-REPROCESSING: **Reprocessing Plant** (3×3): Consumes scrap per cycle and produces exactly one higher-level intermediate product per cycle via weighted random pick. The input quantity, possible output items, per-output weights, and amounts are defined in `recipes.toml [[recipe]]` entries with `building = "reprocessing_plant"` (`inputs`, `outputs[].item`, `outputs[].amount`, `outputs[].weight`). Weights are normalized at load time; their sum does not need to equal 1. The output is rolled at cycle start (see REQ-MAT-CYCLE); the pool of eligible outputs is restricted to implicitly unlocked item types (REQ-LOCK-REPROCESSING-POOL). The output buffer holds at most one cycle's output — see REQ-MAT-OUTPUT-BUFFER-REPROCESSING.
 - REQ-BLD-SHIPYARD: **Shipyard** (4×2): The player selects a schematic. When all required materials — the ship's base materials (`[ship.schematic].materials`) plus the materials of all modules in the configured layout (REQ-MOD-MATERIALS) — are present in its input buffer, the shipyard consumes them and begins a production cycle lasting the ship's base `[ship.schematic].production_time_seconds` plus the sum of production times contributed by all module instances in the configured layout (REQ-MOD-PRODUCTION-TIME). One ship of that type is spawned with the configured modules when the cycle completes. The shipyard cannot start a new cycle while one is in progress. If the player confirms a layout change (REQ-MOD-UI-DIALOG) while a production cycle is in progress, the current cycle is cancelled and all consumed materials are discarded; the shipyard returns to idle with the new layout configuration.
-- REQ-BLD-SALVAGE-BAY: **Salvage Bay** (3×2): A dedicated drop-off point for salvage ships. Scrap delivered here is placed onto connected output belts.
-- REQ-BLD-BELT: **Belt** (1×1): Transports items. A belt tile has one direction (N, S, E, W) set at placement (modified by rotation). Curved belts are auto-derived: when a belt tile's outgoing direction leads into another belt whose direction is orthogonal, the downstream belt is rendered and behaves as a curve. Belt speed is defined in `world.toml [world].belt_speed_tiles_per_second` (REQ-GW-BELT-SPEED).
-- REQ-BLD-SPLITTER: **Splitter** (1×1): Distributes incoming items between two output directions. Each output can optionally have a filter (a list of item types), configurable via the selected building panel; only implicitly unlocked item types are available as filter options (REQ-LOCK-UI-SPLITTER). Routing rules:
+- REQ-BLD-SALVAGE-BAY: **Salvage Bay** (3×2): A dedicated drop-off point for salvage ships. It has an output buffer whose holding capacity is defined by the `output_buffer_capacity` field of the `salvage_bay` entry in `buildings.toml` (rather than by a production cycle, since the Salvage Bay has no recipe). A ship at the bay hands over one unit of scrap per tick while the buffer has free space; a full buffer blocks further drop-off until space frees up (consistent with the buffer-full semantics of REQ-MAT-OUTPUT-BUFFER). Held scrap is pushed onto connected output belts.
+- REQ-BLD-BELT: **Belt** (1×1): Transports items. A belt tile has one direction (N, S, E, W) set at placement (modified by rotation). Curved belts are auto-derived: when a belt tile's outgoing direction leads into another belt whose direction is orthogonal, the downstream belt is rendered and behaves as a curve. Belt speed is defined in `world.toml [world].belt_speed_tiles_per_second` (REQ-GW-BELT-SPEED). A belt accepts items only through a non-output edge (REQ-MAT-ACCEPT-DIR).
+- REQ-BLD-SPLITTER: **Splitter** (1×1): Distributes incoming items between two output directions. Incoming items are accepted only through the splitter's non-output edges (REQ-MAT-ACCEPT-DIR). Each output can optionally have a filter (a list of item types), configurable via the selected building panel; only implicitly unlocked item types are available as filter options (REQ-LOCK-UI-SPLITTER). Routing rules:
   - An item matching only one output's filter is routed to that output.
   - An item matching both outputs' filters is distributed by strict alternation between those outputs.
   - An item matching neither output's filter is routed to the unfiltered output. If both outputs have a filter and the item matches neither, the splitter stalls and moves no items until the situation is resolved.
   - If neither output has a filter, items are distributed by strict alternation.
   - In all alternation cases, if one output is blocked the item goes to the other output until it unblocks.
-- REQ-BLD-TUNNEL-ENTRY: **Tunnel Entry** (1×1): The sending end of a tunnel pair. The player sets a direction (N, S, E, W) at placement, rotatable with R/Shift+R. Items arriving from an adjacent belt tile whose direction points into the entry are forwarded through the tunnel to the paired Tunnel Exit (see REQ-BLD-TUNNEL-PAIR, REQ-BLD-TUNNEL-TRANSIT). If the entry is unpaired, or if the paired exit's output is blocked, the entry blocks like a full belt tile.
+- REQ-BLD-TUNNEL-ENTRY: **Tunnel Entry** (1×1): The sending end of a tunnel pair. The player sets a direction (N, S, E, W) at placement, rotatable with R/Shift+R. Items arriving from an adjacent belt tile on a non-output edge (i.e. not the mouth edge in the entry's facing direction — see REQ-MAT-ACCEPT-DIR) whose direction points into the entry are forwarded through the tunnel to the paired Tunnel Exit (see REQ-BLD-TUNNEL-PAIR, REQ-BLD-TUNNEL-TRANSIT). If the entry is unpaired, or if the paired exit's output is blocked, the entry blocks like a full belt tile.
 - REQ-BLD-TUNNEL-EXIT: **Tunnel Exit** (1×1): The receiving end of a tunnel pair. The player sets a direction at placement, rotatable with R/Shift+R. Items received from the paired Tunnel Entry emerge from the output side of the exit tile — the tile adjacent in the exit's facing direction — continuing in that direction. If the exit is unpaired or its output is blocked, it holds received items until they can advance.
 - REQ-BLD-TUNNEL-PAIR: **Tunnel pairing rules.** Pairing is re-evaluated for all Tunnel Entries whenever any Tunnel Entry or Tunnel Exit is placed or demolished.
   - A Tunnel Entry searches tile-by-tile in its facing direction for a partner. Any tunnel building (entry or exit) that faces a *different* direction is ignored and skipped. The search stops at the first tunnel building that faces the *same* direction as the searching entry.
@@ -138,9 +146,27 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 
 ## Material Transport & Buffers
 
-- REQ-MAT-BELT-ONLY: Materials are transported exclusively via belts, splitters, and tunnels.
-- REQ-MAT-INPUT-PORTS: A building accepts items from any adjacent belt tile on any edge of its footprint (excluding cells occupied by output port(s)) whose direction points toward the building, provided the item is an input required by the currently selected recipe and the matching per-material input buffer has free space.
-- REQ-MAT-OUTPUT-PORT: Each building has one or more fixed output port(s) defined by its surface_mask (direction determined by rotation). Produced items are placed onto the belt at the output port tile regardless of that belt's direction.
+- REQ-MAT-BELT-ONLY: Materials are transported exclusively via belts, splitters, and tunnels, with one exception: two directly adjacent buildings whose output and input ports meet transfer items straight between them without an intervening transport tile (REQ-MAT-DIRECT-COUPLE).
+- REQ-MAT-INPUT-PORTS: A building accepts items from any adjacent belt tile on any edge of its footprint (excluding cells occupied by output port(s)) whose direction points toward the building, provided the item is an input required by the currently selected recipe and the matching per-material input buffer has free space. An accepted item does not enter the building instantly; it is removed from the belt and travels inward across the input port's footprint cell on that port's own input belt before being added to the buffer (REQ-MAT-INPUT-INTAKE).
+- REQ-MAT-INPUT-INTAKE: Accepted input items travel into a building as an animation rather than vanishing off the belt instantly — the input-side mirror of REQ-MAT-OUTPUT-EMERGE. Each input port has its own **input belt** — a virtual belt tile occupying the input port's footprint cell (the body cell the feeding belt points into), oriented in the port's inward flow direction, with progress 0.0 at the outer edge adjacent to the feeding belt and 0.5 at the tile centre. It reuses the belt subsystem: movement at belt speed (REQ-GW-BELT-SPEED), item rendering and spacing (REQ-GW-TILE-SIZE), and capacity/packing (REQ-GW-BELT-CAPACITY), but restricted to the 0.0→0.5 half of the tile. This applies to every building that pulls items from adjacent belts into an input buffer (Smelter, Assembler, Reprocessing Plant, Shipyard); a building may run several input belts at once when belts feed it from more than one side. The HQ is included with the one difference noted below.
+  - **Acceptance & reservation.** The acceptance test of REQ-MAT-INPUT-PORTS is unchanged — an item is accepted only if it is a required input whose per-material input buffer has space — except that "has space" now counts both the items already buffered **and** the items of that material currently travelling on the building's input belts (reserved but not yet arrived), so the total (buffered + in-transit) never exceeds that material's buffer cap (REQ-MAT-INPUT-BUFFER). An item that fails this test is not placed on an input belt and stays on the feeding belt exactly as before, so items that are not required inputs never enter the building.
+  - **Feeding.** An accepted item is removed from the feeding belt on the same tick it would have been taken without this animation, and placed on the input belt at progress 0.0, reserving a slot in its per-material buffer. (An input belt may also be fed directly by an adjacent producer's output belt rather than by a real belt — see REQ-MAT-DIRECT-COUPLE — with the same reservation and entry rules.) A new item is placed only when the input belt's entry slot at progress 0.0 is free (per REQ-GW-BELT-CAPACITY spacing — no in-transit item within a quarter tile of 0.0). The 0.0→0.5 span holds at most three in-transit items (progress 0.0, 0.25, 0.5); the reservation limit above may permit fewer.
+  - **Travel & arrival.** An in-transit item advances from progress 0.0 to 0.5 at belt speed. On reaching progress 0.5 it leaves the input belt and is added to its per-material input buffer, turning its reservation into buffered stock; only then does it count toward starting a production cycle (REQ-MAT-CYCLE). Because the slot was reserved on entry, arrival always succeeds — there is no deadlock.
+  - **Reservation may delay production.** A reserved item occupies buffer capacity for its whole 0.0→0.5 travel without yet being consumable, so an input-starved building may briefly wait for an in-transit item to arrive before it can start a cycle. This is accepted.
+  - **Clearing.** Clearing the input buffers on a recipe or schematic change (REQ-MAT-INPUT-BUFFER) also discards any items currently travelling on the input belts and releases their reservations.
+  - **HQ.** The HQ has no input buffer (REQ-HQ-BELT-INPUT); a building block accepted at an HQ input port travels its input belt the same way but reserves nothing, and is added to the global building blocks stock (REQ-MAT-GLOBAL-STOCK) on reaching progress 0.5.
+  - **Intake rendering (no pop-out).** Mirror of the emergence rendering in REQ-MAT-OUTPUT-EMERGE: the building is rendered over the input belt, so an in-transit item is occluded while inside the footprint and is only visible as it crosses the outer edge — appearing to sink into the port. The portion inside the footprint is hidden, and the item disappears at the tile centre (progress 0.5) as it enters the buffer.
+- REQ-MAT-OUTPUT-PORT: Each building has one or more fixed output port(s) defined by its surface_mask (direction determined by rotation). Produced items do not appear on the outgoing belt instantly; each item leaves the building by first emerging across the output port tile on that port's own output belt and then transferring onto the adjacent real belt tile (REQ-MAT-OUTPUT-EMERGE). The adjacent belt's direction is otherwise unconstrained (it may flow away from the building or perpendicular to it), except that a belt oriented with its own output edge facing back into the building refuses the transfer and the item stays stuck at the port (REQ-MAT-ACCEPT-DIR, REQ-MAT-OUTPUT-EMERGE).
+- REQ-MAT-OUTPUT-EMERGE: Items emerge from a building output port as an animation rather than popping directly onto the outgoing belt. Each output port has its own **output belt** — a virtual belt tile occupying the output port tile, oriented in the port's facing direction, with progress 0.0 at the tile's inner edge and 1.0 at the outer (port) edge adjacent to the next real belt tile. It reuses the belt subsystem: movement at belt speed (REQ-GW-BELT-SPEED), item rendering and spacing (REQ-GW-TILE-SIZE), and capacity/packing (REQ-GW-BELT-CAPACITY), but restricted to the 0.5→1.0 half of the tile. This applies to every building that outputs items onto belts (Miner, Smelter, Assembler, Reprocessing Plant, Salvage Bay); it does not apply to the Shipyard, which spawns a ship rather than a belt item (REQ-SHP-SPAWN-PLAYER).
+  - **Feeding.** While the output buffer (REQ-MAT-OUTPUT-BUFFER) holds an item that has not yet begun emerging and the output belt's entry slot at progress 0.5 is free (per REQ-GW-BELT-CAPACITY spacing — no emerging item within a quarter tile of progress 0.5), the next buffered item is placed on the output belt at progress 0.5. Because only the 0.5→1.0 span is used, the output belt holds at most three emerging items (progress 0.5, 0.75, 1.0); once that span is full the building places no further items on it even if the output buffer still holds more.
+  - **Cosmetic hold.** An emerging item still counts as residing in the output buffer (REQ-MAT-GLOBAL-STOCK) for the whole animation; it only leaves the building when it transfers onto a real belt tile at progress 1.0. The output belt therefore adds no inventory capacity beyond the output buffer, and clearing the output buffer on a recipe or schematic change (REQ-MAT-OUTPUT-BUFFER) also removes any items currently emerging.
+  - **Travel & handoff.** An emerging item advances from progress 0.5 to 1.0 at belt speed. At progress 1.0 it attempts to transfer onto the adjacent real belt tile using the normal belt hand-off and accept-direction rules (REQ-MAT-OUTPUT-PORT, REQ-MAT-ACCEPT-DIR): the transfer succeeds only if a transport tile exists there, is not oriented with its output edge facing back into the building, and has free space. On success the item leaves the output buffer and becomes an ordinary item on that belt tile. If instead the output port tile is a directly adjacent building's input edge, the item transfers straight into that building (REQ-MAT-DIRECT-COUPLE).
+  - **Stuck items.** If there is no next real belt tile and no directly-coupled building (REQ-MAT-DIRECT-COUPLE), or the transfer is refused or blocked, the emerging item stops at progress 1.0 and is rendered there (still counted in the output buffer). Following items pile up behind it at progress 0.75 and 0.5 per the packing above, and once the 0.5→1.0 span is full no further items emerge until the front item transfers.
+  - **Emergence rendering (no pop-in).** An emerging item must not simply appear at progress 0.5. The output port tile's building is rendered over the output belt, so an emerging item is occluded while inside the footprint and is revealed progressively as it slides past the port edge — appearing to physically emerge from the building. The portion of the item still within the output port tile is hidden; the portion past the outer edge is drawn.
+- REQ-MAT-DIRECT-COUPLE: **Direct port coupling.** Two directly adjacent buildings whose ports meet transfer items between them with no intervening transport tile. A direct coupling exists at a shared edge where a producer building's output port tile (the tile it pushes toward, REQ-MAT-OUTPUT-PORT) is a body cell of a consumer building, and the producer's output direction carries the item across that edge into the consumer through one of the consumer's input edges (any perimeter edge other than the consumer's own output port, per REQ-MAT-INPUT-PORTS). Over a direct coupling the two virtual belts chain end to end: an item that reaches progress 1.0 on the producer's output belt at the shared edge (REQ-MAT-OUTPUT-EMERGE) is handed, instead of onto a real belt tile, directly onto the consumer's input belt at progress 0.0 (REQ-MAT-INPUT-INTAKE) and continues inward to the consumer's buffer — so the item appears to slide continuously across the shared edge from one building into the next.
+  - **Acceptance.** The hand-off obeys the consumer's normal input rules (REQ-MAT-INPUT-PORTS, REQ-MAT-INPUT-INTAKE): it succeeds only if the item is a required input of the consumer whose per-material buffer has space (reservation-aware — buffered + in-transit below the cap) and the consumer's input belt entry at progress 0.0 is free. On success the item leaves the producer's output buffer and reserves a slot in the consumer's input buffer, exactly as a belt-fed intake would. If the consumer does not accept the item — it is not one of its inputs, or the buffer is full, or the input-belt entry is occupied — the item stays stuck at the producer's output port at progress 1.0, exactly as when a downstream belt is blocked (REQ-MAT-OUTPUT-EMERGE stuck items).
+  - **Scope.** Direct coupling is the only case in which materials move between buildings without a belt, splitter, or tunnel (REQ-MAT-BELT-ONLY); it bridges only two buildings that are directly adjacent with meeting output/input ports. Transport tiles feeding a building (belt, splitter, or tunnel exit) continue to work through the normal pull, and a producer still hands off to a transport tile placed in the gap as before; a single such tile between two buildings is unaffected by this requirement.
+- REQ-MAT-ACCEPT-DIR: A transport tile (belt, splitter, tunnel entry, or tunnel exit) accepts an incoming item only through a non-output edge; an item that would enter through one of the tile's output edges is refused. For a belt or a tunnel entry/exit the sole output edge is the one in its facing direction; for a splitter either of its two output directions is an output edge. This applies both to items pushed from an adjacent transport tile and to items deposited by a building's output port (REQ-MAT-OUTPUT-PORT).
 - REQ-MAT-INPUT-BUFFER: Each building has one input buffer per required input material. Each per-material buffer holds up to twice that material's per-cycle requirement. When the player selects a new recipe or schematic, all items in all input buffers are cleared.
 - REQ-MAT-OUTPUT-BUFFER: Each building has an output buffer that holds up to twice the quantity produced by one production cycle. If the output buffer is full, production stops until space is available. When the player selects a new recipe or schematic, all items in the output buffer are cleared (relevant when the adjacent belt is jammed and items have accumulated).
 - REQ-MAT-OUTPUT-BUFFER-REPROCESSING: Exception to REQ-MAT-OUTPUT-BUFFER — the Reprocessing Plant's output buffer holds at most one cycle's output. This prevents exploits where the player stalls the output belt to force the plant to reroll.
@@ -197,6 +223,7 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
   - `surface_mask` — footprint within the ship layout grid (see Module Surface Mask Format).
   - `materials` — list of materials required per instance (added to the ship's build cost).
   - `unlock_at_station_level` — the enemy defence station level at which this module's schematic becomes available for unlock; -1 means the player starts with the module schematic already unlocked.
+  - `unlock_requires` — optional list of prerequisite schematic ids that must already be unlocked before this module's schematic can drop (REQ-LOCK-PREREQ). Defaults to empty.
   - `production_time_seconds` — time added to the ship's production cycle per instance.
   - `fill_color` — fill color used to render this module's cells in the layout grid.
   - `glyph` — single character rendered on this module's cells in the layout grid and preview widget.
@@ -223,12 +250,13 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
   2. The `production_time_seconds` of every module instance in the configured layout.
   3. For every material required (the union of the ship's base materials and all module instance materials, with quantities summed per item type): the recursive production time of that material multiplied by the required quantity (see REQ-THREAT-ITEM).
 
-- REQ-THREAT-ITEM: The threat value of an item type (in seconds) is determined by the recipe that produces it:
-  - **Miner recipe**: the recipe's `duration_seconds`.
-  - **Smelter recipe**: the recipe's `duration_seconds` plus the sum of each input's threat value multiplied by that input's required quantity.
-  - **Assembler recipe**: the recipe's `duration_seconds` plus the sum of each input's threat value multiplied by that input's required quantity.
-  - **Reprocessing-only item** (an item type that has no miner, smelter, or assembler recipe producing it, and is only obtainable via reprocessing): `(scrap_threat × scrap_per_cycle + duration_seconds) / probability`, where `scrap_threat` is the threat value of scrap (see REQ-THREAT-SCRAP), `scrap_per_cycle` is the number of scrap consumed per reprocessing cycle, `duration_seconds` is the reprocessing cycle time, and `probability` is the normalized weight of that item in the reprocessing output pool.
-  - **Multiple recipes**: if an item type can be produced by more than one non-reprocessing recipe (miner, smelter, or assembler), its threat value is the **maximum** across all such recipes. The reprocessing path is only used when no other recipe exists.
+- REQ-THREAT-ITEM: The threat value of an item type (in production-seconds **per unit**) is determined by the recipe that produces it:
+  - **Miner recipe**: `duration_seconds / output_amount`, where `output_amount` is the number of units produced per cycle.
+  - **Smelter recipe**: `(duration_seconds + Σ (input_threat × input_amount)) / output_amount`, where the sum is over all inputs.
+  - **Assembler recipe**: `(duration_seconds + Σ (input_threat × input_amount)) / output_amount`, where the sum is over all inputs.
+  - **Reprocessing-only item** (an item type that has no miner, smelter, or assembler recipe producing it, and is only obtainable via reprocessing): `(scrap_threat × scrap_per_cycle + duration_seconds) / probability`, where `scrap_threat` is the threat value of scrap (see REQ-THREAT-SCRAP), `scrap_per_cycle` is the number of scrap consumed per reprocessing cycle, `duration_seconds` is the reprocessing cycle time, and `probability` is the normalized weight of that item in the reprocessing output pool. (Reprocessing output amounts are 1 in practice, so per-unit division is already implicit in the formula.)
+  - **Multiple recipes**: if an item type can be produced by more than one non-reprocessing recipe (miner, smelter, or assembler), its threat value is the **maximum** across **all** such eligible recipes, and the threat is committed only once every eligible recipe is computable (so a shallow shortcut recipe that resolves earlier than a deeper base recipe cannot lower the item's threat). The reprocessing path is only used when no other recipe exists. If recipe cycles prevent full resolution, the max over the currently computable subset is used as a fallback.
+  - **Scrap-consuming recipe fallback**: a non-reprocessing recipe that takes `scrap` as an input participates in an item's threat computation only if no scrap-free recipe (miner, smelter, or assembler) produces that item. This mirrors the reprocessing fallback rule and prevents the scrap-to-ingot smelter recipe from inflating basic material threats via the max rule.
 
 - REQ-THREAT-SCRAP: The threat value of scrap is the constant `1 / world.toml [world].scrap_per_threat`. This is the exact inverse of the scrap-drop conversion in REQ-RES-SCRAP-DROP, so a destroyed ship drops scrap worth precisely its own threat cost. Because scrap threat is now a fixed constant, it no longer depends on any ship's threat cost, removing the potential circularity with REQ-MOD-THREAT for ships built from reprocessing-only materials.
 - REQ-MOD-STAT-CALC: For each stat (on the ship hull or on a capability module instance), the final value is computed as: `final = base × total_multiplier + total_additive`, where:
@@ -249,7 +277,7 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 
 ### Module UI
 
-- REQ-MOD-UI-PREVIEW: When a schematic is selected in a shipyard's selected building panel, a small non-interactive **ship layout preview** widget is shown below the schematic selection button (REQ-UI-SELECT-BUTTON). The preview renders the ship's layout grid at a reduced scale: buildable cells without a module are shown as white, non-buildable cells are shown as black, and cells occupied by a module are shown in that module's `fill_color` with the module's `glyph` character. Below the preview, a "Configure" button is shown.
+- REQ-MOD-UI-PREVIEW: For a selected shipyard (operational building or construction site), the selected building panel always shows a small non-interactive **ship layout preview** widget below the schematic selection button (REQ-UI-SELECT-BUTTON) and a "Configure" button below the preview. Both are **disabled while no schematic is selected**, and enabled once one is; the preview then shows an empty placeholder in place of a layout grid. When a schematic is selected, the preview renders the ship's layout grid at a reduced scale: buildable cells without a module are shown as white, non-buildable cells are shown as black, and cells occupied by a module are shown in that module's `fill_color` with the module's `glyph` character. For non-shipyard buildings, neither the preview nor the "Configure" button is shown.
 - REQ-MOD-UI-DIALOG: Clicking the "Configure" button opens the **layout configuration dialog** as a modal. While the dialog is open, the game is paused (speed set to 0×). On close, the game speed is restored to what it was before the dialog was opened.
 
   The dialog contains:
@@ -259,6 +287,10 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
   - **Right** (below the grid): The layout blueprint panel (see REQ-MOD-UI-BLUEPRINT-PANEL through REQ-MOD-UI-BLUEPRINT-FILE-LOAD).
   - **Bottom**: A "Confirm" button and a "Cancel" button. Cancel discards all changes made in this dialog session and closes the dialog. Confirm applies the changes: the shipyard's configured layout is updated, the required materials and cycle time displayed in the selected building panel are recalculated, and the ship layout preview is refreshed.
 
+- REQ-MOD-UI-AUTO-DIALOG: When the player selects a schematic for a shipyard (operational building or construction site) through the schematic selection dialog (REQ-UI-SELECT-BUTTON), and the chosen schematic **differs** from the shipyard's current schematic, the layout configuration dialog (REQ-MOD-UI-DIALOG) opens automatically and immediately once the selection dialog closes — exactly as if the player had then clicked "Configure". Re-selecting the schematic already set does not reopen the dialog. This auto-open applies only to the manual schematic selection dialog; schematic changes applied via the copy-settings gesture (REQ-BLD-COPY-CONFIG) or blueprint placement (REQ-UI-BLUEPRINT-PLACE) do **not** auto-open the dialog. The player may still cancel the auto-opened dialog (REQ-MOD-UI-DIALOG), which leaves the newly selected schematic in place with its default empty layout; the "Configure" button (REQ-MOD-UI-PREVIEW) remains available to open the dialog again later.
+
+- REQ-MOD-UI-MODULE-TOOLTIP: Each module selection button in the layout configuration dialog (REQ-MOD-UI-DIALOG) shows a hover tooltip with the descriptive text defined for that module type in `modules.toml` (the optional per-module tooltip field). If a module type defines no tooltip text, its button shows no tooltip. The "Remove" button is not a module type and has no config-defined tooltip.
+
 - REQ-MOD-UI-STATS-PANEL: The **ship stats panel** in the layout configuration dialog shows the stats of the currently configured ship layout as they would be computed, incorporating all passive module modifiers per REQ-MOD-STAT-CALC. The panel updates in real time whenever modules are placed or removed in the layout grid.
 
   The panel always shows all hull stats as final computed values:
@@ -307,13 +339,15 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
   - All **ship schematics** and **module schematics** whose `unlock_at_station_level` is ≥ 0 and ≤ the level of the destroyed station set, and which have not yet been unlocked.
   - All **assembler recipe schematics** whose `unlock_at_station_level` is ≥ 0 and ≤ the level of the destroyed station set, whose output item is currently implicitly unlocked (REQ-LOCK-IMPLICIT), and which have not yet been awarded.
 
-  Each option in the dialog displays: the schematic name (ship `display_name` from `ships.toml`, module `id` from `modules.toml`, or the output item type for assembler recipes) and the schematic type (ship, module, or assembler recipe). The artifact option (if present) is displayed as a distinct entry with the name "Artifact".
+  In addition to the conditions above, a schematic is included in the eligible drop pool only when every prerequisite in its optional `unlock_requires` list is currently satisfied (REQ-LOCK-PREREQ). Because the pool is rebuilt for each drop, a schematic gated behind prerequisites first appears only after all of its prerequisites have themselves been unlocked.
 
-  Each option additionally displays a vertical list of item names labeled "Unlocks recipes for:", showing which recipes would newly become implicitly unlocked (REQ-LOCK-IMPLICIT) if this option were selected — specifically, the output items of miner recipes and assembler recipes (without `unlock_at_station_level`) that are not currently implicitly unlocked but would become so after applying this option's effect:
+  Each option in the dialog displays: the schematic name (ship `id` from `ships.toml`, module `id` from `modules.toml`, or assembler recipe `id` from `recipes.toml`) and the schematic type (ship, module, or assembler recipe). The artifact option (if present) is displayed as a distinct entry with the name "Artifact".
+
+  Each option additionally displays a vertical list of recipe names labeled "Unlocks recipes:", showing which miner and assembler recipes would newly become implicitly unlocked (REQ-LOCK-IMPLICIT) if this option were selected — specifically, the miner recipes and assembler recipes (without `unlock_at_station_level`) that are not currently implicitly unlocked but would become so after applying this option's effect:
   - For a ship or module schematic, its `materials` are added to the base set per REQ-LOCK-IMPLICIT step 1a before recomputation.
   - For an assembler recipe schematic, its output item is added to the base set per REQ-LOCK-IMPLICIT step 1b before recomputation.
 
-  Item names are deduplicated and sorted alphabetically. If no recipes would be newly unlocked, the list shows "None".
+  Each recipe is listed by its `id` (using the same display convention as the assembler recipe-selection dialog), sorted alphabetically. Hovering a recipe in this list displays the recipe info tooltip described for a recipe in REQ-UI-SELECT-TOOLTIP (the recipe name; the name and quantity of each input item; the completion time; and the name and quantity of the produced output item). If no recipes would be newly unlocked, the list shows "None".
 
   The player selects one option by clicking it. If the player selects the artifact option, the player's artifact count is incremented by 1 (REQ-WIN-ARTIFACT-COUNT) and the dialog closes; no schematic is applied. Otherwise, the selected schematic is applied and the dialog closes:
 
@@ -325,6 +359,8 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 
 - REQ-LOCK-EXPLICIT: Ship schematics, module schematics, and **assembler recipe schematics** (assembler recipes in `recipes.toml` that define `unlock_at_station_level`) are **explicitly** locked or unlocked. A schematic starts unlocked if its `unlock_at_station_level` is -1; all others start locked. Locked schematics are unlocked only by REQ-DEF-SCHEMATIC-DROP. Once unlocked, a schematic is never re-locked within a run; lock states reset to their initial values on Restart (REQ-CFG-RELOAD). Unlike ship and module schematics, an assembler recipe schematic is removed from the drop pool permanently once awarded and cannot be dropped again.
 
+- REQ-LOCK-PREREQ: A ship schematic, module schematic, or assembler recipe schematic may optionally define `unlock_requires` — a list of prerequisite schematic ids (a ship `id`, module `id`, or assembler recipe `id`) that must already be unlocked before this schematic may enter the drop pool. A prerequisite is **satisfied** only when the schematic it names is currently **explicitly unlocked** (REQ-LOCK-EXPLICIT) — that is, the referenced schematic either started unlocked with `unlock_at_station_level = -1` or has been awarded via a drop. This prerequisite check is applied in addition to the per-schematic conditions in REQ-DEF-SCHEMATIC-DROP: a schematic enters the eligible drop pool only when its `unlock_at_station_level` condition is met, it has not yet been unlocked/awarded, and every id in its `unlock_requires` is satisfied. `unlock_requires` defaults to empty (no prerequisites), which reproduces the prior behaviour. The check is re-evaluated against the current explicit-unlock set every time a drop pool is built (after each REQ-DEF-SCHEMATIC-DROP and on Restart per REQ-CFG-RELOAD), so a gated schematic becomes eligible in the first drop after its last prerequisite is unlocked. Every id listed in any `unlock_requires` must resolve to a schematic that is itself explicitly unlockable (a ship, module, or assembler recipe schematic defined in config); an id that names no such schematic is a configuration error that fails config load with a descriptive message (config is loaded at startup and reloaded on Restart, REQ-CFG-RELOAD). A schematic that lists itself, or a cycle of mutually dependent prerequisites, is not a load error but can never become eligible, since no schematic in the cycle can be the first to unlock.
+
 - REQ-LOCK-IMPLICIT: Item types and miner/assembler recipes are **implicitly** unlocked or locked based on the current set of unlocked ship, module, and assembler recipe schematics. The implicit unlock set is recomputed whenever any schematic changes lock state (on Restart or after REQ-DEF-SCHEMATIC-DROP). Computation:
   1. Start with the union of: (a) all item types listed in `materials` across all currently unlocked ship schematics and all currently unlocked module schematics, and (b) the output item type of every currently explicitly unlocked assembler recipe schematic (REQ-LOCK-EXPLICIT).
   2. For each item type in the current set: for every recipe (miner, smelter, or assembler) that produces it — skipping any assembler recipe schematic that defines `unlock_at_station_level` and is not yet explicitly unlocked — add each of that recipe's input item types to the set. If the recipe is a miner recipe or an assembler recipe that does not define `unlock_at_station_level`, mark it as implicitly unlocked. Explicitly unlocked assembler recipe schematics are available in the assembler recipe-selection dialog by virtue of REQ-LOCK-EXPLICIT; their inputs are also added to the implicit set in this step.
@@ -361,7 +397,7 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 ## Asteroid Expansion
 
 - REQ-EXP-UNLOCK: The player can unlock additional asteroid tile columns to the left of the existing asteroid by spending building blocks from the global stock.
-- REQ-EXP-COST: Each expansion adds `world.toml [expansion].columns_per_expansion` columns and costs `[expansion].cost_building_blocks` building blocks.
+- REQ-EXP-COST: Each expansion adds `world.toml [expansion].columns_per_expansion` columns. The building block cost of an expansion is defined by the formula `world.toml [expansion].cost_building_blocks_formula`, where `x` is the number of expansions already purchased (0 for the first expansion, incrementing by 1 for each subsequent expansion). The formula is evaluated at purchase time and its result is floored to an integer number of building blocks.
 
 ## UI
 
@@ -386,15 +422,24 @@ The screen is divided into two columns: a main column (75% width) containing the
            (75% width)                   (25% width)
 ```
 
-- REQ-UI-HEADER: The header bar spans the width of the game world column (75% of the screen width) and always shows the elapsed survival time, the current global building blocks stock, and the artifact count (REQ-WIN-ARTIFACT-COUNT) displayed as `Artifacts: x/y` (where `x` is the current artifact count and `y` is `world.toml [world].artifact_win_count`) on the left, the boss wave counter and boss countdown (REQ-UI-BOSS-STATUS) to the left of the speed buttons, and game speed controls on the right.
+- REQ-UI-HEADER: The header bar spans the width of the game world column (75% of the screen width) and always shows the elapsed survival time, the current global building blocks stock, and the artifact count (REQ-WIN-ARTIFACT-COUNT) displayed as `Artifacts: x/y` (where `x` is the current artifact count and `y` is `world.toml [world].artifact_win_count`) on the left, the boss wave counter and boss countdown (REQ-UI-BOSS-STATUS) and an asteroid expansion button (REQ-UI-EXPAND-BUTTON) to the left of the speed buttons, and game speed controls on the right.
+- REQ-UI-BLOCKS-TOOLTIP: The header bar's building blocks stock display (REQ-UI-HEADER) shows a hover tooltip with the descriptive text defined in `world.toml [world].building_blocks_tooltip` — intended to tell the player what building blocks are used for and how to obtain them. If the field is unset, the stock display shows no tooltip. This tooltip is distinct from the build/module button tooltips (REQ-UI-BUILD-TOOLTIP, REQ-MOD-UI-MODULE-TOOLTIP).
 - REQ-UI-BOSS-STATUS: The header bar displays, to the left of the speed buttons, the current boss wave counter (REQ-WAV-BOSS-COUNTER) and the time remaining on the boss countdown (REQ-WAV-BOSS-COUNTDOWN). The boss wave counter is shown as `Boss Wave #<x>` and the countdown as `Next boss: <M:SS>`, where `<M:SS>` is the remaining seconds formatted as whole minutes and two-digit seconds. Both values update continuously as the simulation runs.
 - REQ-UI-SPEED: The game speed controls in the header bar are buttons for 0×, 0.5×, 1×, 2×, and 4× speed. The currently active speed is shown as selected. All game simulation (production, movement, threat accumulation, wave timing) scales with the selected speed. 0× pauses the game.
+- REQ-UI-EXPAND-BUTTON: The header bar shows an asteroid expansion button captioned `Expand: <x> Blocks`, where `<x>` is the current expansion cost computed from `world.toml [expansion].cost_building_blocks_formula` at the current number of purchased expansions (REQ-EXP-COST). Clicking the button unlocks the next asteroid expansion (REQ-EXP-UNLOCK, REQ-GW-ASTEROID-EXPAND), spending that many building blocks from the global stock. The button is disabled when the player cannot currently afford the cost (consistent with REQ-UI-BUILD-DISABLED). The caption updates as the cost changes with each purchased expansion.
 - REQ-UI-WORLD-SIZE: The game world view occupies the full height below the header bar in the main column (75% of the screen width).
 - REQ-UI-PANEL-COLUMN: The side panel column occupies 25% of the screen width and the full screen height. It is divided into three equal-height panels stacked top to bottom: selected building panel (top), build button grid (middle), and blueprint panel (bottom).
+- REQ-UI-MODAL-DIM: While a modal dialog, menu, or full-screen state screen is open on top of the game, a transparent black overlay (a dim/scrim) is drawn over the **entire game window** — the header bar, the game world view, and the side panel column — behind that modal, so the game reads as inactive while the modal holds focus. The overlay is shown for every modal that auto-pauses the simulation — the escape menu (REQ-UI-GAME-MENU), the recipe/schematic selection dialog (REQ-UI-SELECT-BUTTON), the layout configuration dialog (REQ-MOD-UI-DIALOG), and the schematic choice dialog (REQ-DEF-SCHEMATIC-DROP) — as well as the game-over screen (REQ-HQ-GAME-OVER) and the win screen (REQ-WIN-SCREEN), which end rather than pause the game. When modals are nested (for example the Create Blueprint name dialog (REQ-MOD-UI-BLUEPRINT-CREATE) opened from the layout configuration dialog), only a single dim is shown over the game window; nested modals do not stack additional overlays. The dim color and opacity are read from `visuals.toml [overlays]` (a semi-transparent black modal-dim color), consistent with the other overlay colors. The overlay is presentation-only and has no effect on the simulation.
 
 ### Game World
 
-- REQ-UI-SCROLL: The player scrolls the view horizontally across the scrollable area by pressing A (scroll left) and D (scroll right).
+- REQ-UI-SCROLL: The player scrolls the view horizontally across the scrollable area by pressing A (scroll left) and D (scroll right). The pan speed is not constant; it varies with the view's position per REQ-UI-SCROLL-SPEED.
+- REQ-UI-SCROLL-SPEED: The horizontal pan speed varies with position so the player crosses the empty middle of the world quickly while retaining fine control near the asteroid and near the front line. Two pan speeds are read from `world.toml [scroll]`: `pan_speed_slow_tiles_per_second` (the base speed, used while the view is over the asteroid and player buffer zone) and `pan_speed_fast_tiles_per_second` (the faster speed, used while the view is over the contest zone). Both are expressed in tiles per second and apply equally to the A and D scroll directions. The current pan speed is a function of the view's horizontal center X (REQ-GW-REGIONS defines the regions):
+  - **Flat regions:** while the view center is left of the contest zone (over the asteroid or player buffer zone) and outside any ramp band, the pan speed is the slow speed; while the view center is inside the contest zone and outside any ramp band, the pan speed is the fast speed.
+  - **Ramp bands:** a transition ramp band of width `world.toml [scroll].pan_ramp_band_width_tiles` tiles straddles each contest-zone boundary (the player defence stations on the left, the enemy defence stations on the right), centered on the boundary with half the band width on each side. While the view center is within a ramp band, the pan speed is linearly interpolated between the slow speed at the band's outer (non-contest-zone) edge and the fast speed at the band's inner (contest-zone) edge, by the view center's fractional position across the band. This produces smooth speed changes when entering and exiting the fast contest-zone range rather than an abrupt jump.
+  - **Narrow contest zone:** should the two ramp bands overlap (a contest zone narrower than the band width), each ramp is clamped at the contest-zone center so the bands do not cross; the fast plateau then reduces to a single point at the center and the peak speed there may be below the fast speed.
+
+  Because the contest-zone boundaries shift as the scrollable area grows with each push (REQ-GW-PUSH-EXPAND, REQ-GW-SCROLL-LIMIT), the ramp bands are recomputed from the current contest-zone boundaries. This is a presentation-only concern and does not affect the simulation, consistent with REQ-UI-NO-ZOOM.
 - REQ-UI-CONSTRUCTION-PROGRESS: Construction sites display the building's glyph centered on the footprint (same as an operational building). Below the glyph — or centered on the footprint if the building has no glyph — a construction progress percentage is shown (integer, e.g. `42%`), increasing from 0% to 100% as construction completes.
 - REQ-UI-PORT-GLYPH: Every output port of every building is indicated by a directional glyph drawn on the port's tile. The glyph is a `>` rotated to face the port's exit direction (`>` for East, `^` for North, `<` for West, `v` for South). It is drawn at the midpoint between the tile center and the tile edge that the port exits through (i.e. halfway from center toward the exit edge). The indicator is rendered for all building states: operational buildings, construction sites, and the builder-mode ghost. Buildings with multiple output ports (e.g. splitters) show one indicator per port.
 - REQ-UI-HP-BARS: All entities with HP — the HQ, player and enemy defence stations, and player and enemy ships — render an HP bar below them. The bar is always visible regardless of current HP. The bar's filled portion represents the fraction of current HP to maximum HP.
@@ -406,6 +451,7 @@ The screen is divided into two columns: a main column (75% width) containing the
   - **A / D** — scroll the view left / right (REQ-UI-SCROLL).
   - **Q** — context-sensitive. If a build mode is active (builder mode or blueprint placement mode), pressing Q exits it. Otherwise, pressing Q toggles demolish mode: it enters demolish mode if inactive, or exits demolish mode if already active. (See also REQ-UI-DEMOLISH-BUTTON for the equivalent button.)
   - **R / Shift+R** — in builder mode, rotate the ghost counter-clockwise / clockwise (REQ-BLD-ROTATE).
+  - **T** — create a temporary blueprint from the current selection and enter its placement mode (REQ-UI-BLUEPRINT-TEMP).
   - **Escape** — opens the escape menu (REQ-UI-GAME-MENU).
   - **Build mode selection** — pressing a build hotkey activates builder mode for the corresponding building type, equivalent to clicking its build button (REQ-BLD-BUILDER-MODE):
     - **1** — Belt, **2** — Splitter, **3** — Tunnel Entry, **4** — Tunnel Exit.
@@ -432,35 +478,49 @@ The screen is divided into two columns: a main column (75% width) containing the
 
 ### Selected Building Panel
 
-- REQ-UI-EMPTY-SELECTION: When no building is selected, the panel is empty.
+- REQ-UI-EMPTY-SELECTION: When nothing is selected (no building, construction site, ship, defence station, or scrap pile), the panel is empty.
 - REQ-UI-SINGLE-SELECTION: When one building is selected, the panel shows: building name, current recipe or schematic selection, input buffer contents, and output buffer contents. Buffer counts are displayed as `a/b` where `a` is the current item count and `b` is the per-cycle amount (items consumed per run for inputs; items produced per run for outputs). For a selected construction site, the recipe/schematic selection (and, for a shipyard, the layout preview and "Configure" button) are shown but the buffer rows are omitted (REQ-BLD-SITE-CONFIG).
 - REQ-UI-PRODUCTION-PROGRESS: For buildings that produce items or ships (miner, smelter, assembler, reprocessing plant, shipyard), the selected building panel also shows: (a) the cycle time of the currently selected recipe or schematic in seconds, and (b) the completion percentage of the active production cycle as an integer (e.g. `42%`), or the text `idle` when no production cycle is active. When no recipe or schematic is selected, neither the cycle time nor the progress indicator is shown.
-- REQ-UI-MULTI-SELECT: The player selects multiple buildings by box-drag or by Ctrl+clicking individual buildings to add or remove them from the selection.
-- REQ-UI-MULTI-SELECTION: When multiple buildings are selected, the panel shows how many of each building type are selected. No per-building detail is shown.
+- REQ-UI-MULTI-SELECT: The player selects multiple buildings by box-drag or by Ctrl+clicking individual buildings to add or remove them from the selection. A box-drag that covers at least one building selects buildings (any scrap piles within the box are ignored); a box-drag that covers no buildings but does cover scrap piles selects those scrap piles instead (REQ-UI-SCRAP-MULTI-SELECT).
+- REQ-UI-MULTI-SELECTION: When multiple buildings are selected, the panel shows how many of each building type are selected. No per-building detail is shown. The panel additionally shows the **total building block cost** of the selection — the sum of each selected building's placement cost (`buildings.toml [[building]].cost`, per REQ-BLD-COST), counting only player-placeable buildings (buildings with a button in the build button grid); non-player-placeable buildings (the HQ and defence stations) are excluded from the total, consistent with the blueprint total (REQ-UI-BLUEPRINT-BUTTON). Construction sites count at their building type's full placement cost regardless of construction progress.
 - REQ-UI-CONFIG-INLINE: Recipe and schematic configuration for a selected building is shown within this panel. Recipe selection (miner, assembler) and schematic selection (shipyard) use the selection button and dialog (REQ-UI-SELECT-BUTTON) rather than an inline control. For shipyards, the panel additionally shows the ship layout preview and "Configure" button below the schematic selection button (REQ-MOD-UI-PREVIEW).
 - REQ-UI-SELECT-BUTTON: **Recipe and schematic selection control.** Recipe selection (Miner ore type, Assembler recipe) and schematic selection (Shipyard) are each presented in the selected building panel as a single **selection button** whose caption is the name of the currently selected recipe or schematic, or a placeholder ("Select recipe" / "Select schematic") when none is selected. Clicking the button opens a modal **selection dialog** that pauses the game (speed set to 0×; on close, the speed is restored to what it was before the dialog was opened). The dialog contains a grid of option buttons, one per selectable option — only options that are currently unlocked are shown (REQ-LOCK-UI-RECIPE for recipes, REQ-LOCK-UI-SCHEMATIC for schematics). Hovering an option button shows the selection info tooltip (REQ-UI-SELECT-TOOLTIP). Clicking an option button selects that recipe/schematic, closes the dialog, and updates the selection button's caption in the selected building panel. The dialog can be dismissed without changing the current selection (e.g. closing it without clicking an option). Selecting a new recipe or schematic has the same effects as before (REQ-MAT-INPUT-BUFFER, REQ-MAT-OUTPUT-BUFFER, REQ-BLD-SHIPYARD).
 - REQ-UI-SELECT-TOOLTIP: **Selection info tooltip.** Hovering an option button in the selection dialog (REQ-UI-SELECT-BUTTON), and hovering the selection button in the selected building panel when a selection is set, displays an info tooltip:
   - For a **recipe** (Miner or Assembler): the recipe name; the name and quantity of each input item (no inputs are listed for miner recipes, which consume nothing); the completion time (`duration_seconds`); and the name and quantity of the produced output item.
   - For a **ship schematic** (Shipyard): the ship's `display_name`; the name and quantity of each base required material (`[ship.schematic].materials`, excluding any module contributions); the base production time (`[ship.schematic].production_time_seconds`); and "Produces: 1 <ship display name>".
 - REQ-UI-BELT-CLEAR: When one or more belt, splitter, tunnel entry, or tunnel exit tiles are selected, the panel shows a "Clear" button that removes all items from the selected tiles. Clearing a tunnel entry or exit also discards all items currently in transit through that tunnel (REQ-BLD-TUNNEL-TRANSIT). This can be used to resolve stalled belts, splitters, and tunnels.
-- REQ-UI-ENTITY-CLICK-SELECT: The player can click any ship (player or enemy) or any defence station (player or enemy) in the game world to select it. Clicking a ship or defence station clears any existing selection and establishes a single-entity selection containing only that entity. Ships and defence stations cannot participate in multi-select together with buildings. Clicking empty world space (no building, ship, or defence station) clears the selection.
+- REQ-UI-ENTITY-CLICK-SELECT: The player can click any ship (player or enemy) or any defence station (player or enemy) in the game world to select it. Clicking a ship or defence station clears any existing selection and establishes a single-entity selection containing only that entity. Ships and defence stations cannot participate in multi-select together with buildings. Clicking a scrap pile instead establishes a scrap selection (REQ-UI-SCRAP-CLICK-SELECT). Clicking empty world space (no building, ship, defence station, or scrap pile) clears the selection.
 - REQ-UI-SHIP-STATS-PANEL: When a single ship is selected (REQ-UI-ENTITY-CLICK-SELECT), the selected building panel shows a **ship stats panel**. The panel structure mirrors REQ-MOD-UI-STATS-PANEL but reflects the ship's actual live state: stats are computed from its installed modules per REQ-MOD-STAT-CALC. The panel always shows all hull stats: HP (current / maximum), max linear speed, sensor range, main acceleration, maneuvering acceleration, angular acceleration, and max rotation speed. In addition, capability module summaries are shown conditioned on which module types are installed, using the same aggregation rules as REQ-MOD-UI-STATS-PANEL: weapons (combined DPS, maximum range), salvage (combined collection rate, maximum range), and repair (combined repair rate, maximum range), each section appearing only if at least one instance of that module type is installed. While debug draw mode is active (REQ-UI-DEBUG-DRAW), the panel additionally shows the ship's derived threat cost (REQ-MOD-THREAT).
+- REQ-UI-SHIP-BEHAVIOR: The ship stats panel (REQ-UI-SHIP-STATS-PANEL) additionally displays the selected ship's **current behavior** — a single label naming the top-priority behavior currently governing the ship's navigation, as resolved by the fixed-priority behavior arbitration. Only the winning behavior is named; lower-priority behaviors that are suppressed are not shown, and neither are the salvage/repair cycles that run regardless of the active behavior (REQ-SHP-SALVAGE, REQ-SHP-REPAIR). The label updates live as the ship's behavior changes, and it is always shown (independent of debug draw mode, unlike the threat-cost line of REQ-UI-SHIP-STATS-PANEL). This applies to both player and enemy ships (REQ-UI-ENTITY-CLICK-SELECT); enemy ships only ever show **Engaging** or **Advancing**. The behavior labels (all wrapped in `tr()`) are:
+  - **Retreating** — the ship is retreating (REQ-SHP-RETREAT).
+  - **Engaging** — the ship is engaging a combat target (player: REQ-SHP-COMBAT; enemy: REQ-SHP-ENEMY-AI).
+  - **Salvaging** — the ship is executing salvage navigation: seeking scrap, collecting, or delivering to a Salvage Bay (REQ-SHP-SALVAGE).
+  - **Repairing** — the ship is navigating to a repair target (REQ-SHP-REPAIR).
+  - **Rallying** — the ship is moving to or orbiting the rally point (REQ-SHP-RALLY).
+  - **Standby** — the ship is holding with its fleet (REQ-SHP-STANDBY).
+  - **Advancing** — the ship is executing the baseline forward advance with no higher-priority behavior active (player: REQ-SHP-COMBAT advance toward the enemy; enemy: REQ-SHP-ENEMY-AI advance toward the asteroid).
 - REQ-UI-STATION-STATS-PANEL: When a single defence station is selected (REQ-UI-ENTITY-CLICK-SELECT), the selected building panel shows a **station stats panel** displaying the station's stats computed at its current level: HP (current / maximum), damage, range, and fire rate.
+- REQ-UI-SCRAP-CLICK-SELECT: The player can click any scrap pile (REQ-RES-SCRAP-DROP) in the game world to select it. Scrap forms its own selection category: clicking a scrap pile clears any existing selection and establishes a scrap selection containing only that pile. Scrap piles cannot participate in a selection together with buildings, ships, or defence stations. Hit-testing prioritizes actors over scrap: when a building, ship, or defence station lies under the cursor at the same point as a scrap pile, that object is selected in preference to the scrap; a scrap pile is selected only when no building, ship, or defence station is under the cursor. A selected scrap pile that despawns or is fully collected (REQ-RES-SCRAP-DROP) is removed from the selection; once the last selected pile is gone, the selection becomes empty (REQ-UI-EMPTY-SELECTION).
+- REQ-UI-SCRAP-MULTI-SELECT: Multiple scrap piles can be selected by box-drag or by Ctrl+clicking individual piles to add or remove them from the selection, mirroring building multi-select (REQ-UI-MULTI-SELECT). A scrap selection contains only scrap piles. Because scrap cannot mix with other object types (REQ-UI-SCRAP-CLICK-SELECT), Ctrl+clicking a scrap pile while a building, ship, or defence station selection is active first clears that selection and begins a scrap selection; conversely, selecting a building, ship, or defence station while a scrap selection is active clears the scrap selection. Box-drag disambiguation between buildings and scrap follows REQ-UI-MULTI-SELECT (a box covering any building selects buildings; a box covering scrap but no buildings selects the scrap).
+- REQ-UI-SCRAP-PANEL: When one or more scrap piles are selected, the selected building panel shows the **total remaining scrap amount** across all selected piles — the sum of the piles' current remaining amounts (REQ-RES-SCRAP-DROP), e.g. "Scrap: 47". The same summed-amount display is used whether one pile or many are selected; no per-pile detail and no pile count are shown. The displayed total updates as selected piles are partially collected or despawn (REQ-UI-SCRAP-CLICK-SELECT).
 
 ### Build Button Grid
 
 - REQ-UI-BUILD-GRID: All placeable building types are shown as a flat grid of buttons with no grouping.
 - REQ-UI-BUILD-COST: Each button caption shows the building name and its building block cost, e.g. "Belt: 2 Blocks".
+- REQ-UI-BUILD-TOOLTIP: Each building-type button shows a hover tooltip with the descriptive text defined for that building type in `buildings.toml` (the optional per-building tooltip field). This tooltip is distinct from the recipe/schematic selection tooltip (REQ-UI-SELECT-TOOLTIP). If a building type defines no tooltip text, its button shows no tooltip. The Demolish button (REQ-UI-DEMOLISH-BUTTON) is not a building type and has no config-defined tooltip.
 - REQ-UI-BUILD-DISABLED: Buttons for buildings the player cannot currently afford are shown as disabled.
 - REQ-UI-DEMOLISH-BUTTON: A dedicated **Demolish** button is shown in the build button grid. Clicking it toggles demolish mode on and off, equivalent to the Q demolish toggle (REQ-UI-HOTKEYS). The button is shown in a visually active/pressed state while demolish mode is active.
 
 ### Blueprint Panel
 
-- REQ-UI-BLUEPRINT-PANEL: The blueprint panel is shown to the right of the build button grid. It contains, from top to bottom: a "Create Blueprint" button, and a list of blueprint entries (one per saved blueprint, in creation order).
+- REQ-UI-BLUEPRINT-PANEL: The blueprint panel is shown to the right of the build button grid. It contains, from top to bottom: a "Create Blueprint" button, and a list of blueprint entries (one per saved blueprint, in creation order). The panel has no Save or Load buttons; blueprints are persisted automatically (REQ-UI-BLUEPRINT-SAVE) and restored at startup (REQ-UI-BLUEPRINT-LOAD).
 
-- REQ-UI-BLUEPRINT-CREATE: The "Create Blueprint" button is enabled only when at least one player-placeable building (i.e. a building with a button in the build button grid) is currently selected; non-player-placeable buildings (HQ, defence stations) in the selection do not count toward this condition. When clicked, a modal dialog appears prompting the player to enter a name. The dialog has Confirm and Cancel buttons. Clicking Cancel closes the dialog with no effect. Clicking Confirm with a non-empty name creates a blueprint from the current selection, silently excluding any non-player-placeable buildings, and appends its button to the blueprint list.
+- REQ-UI-BLUEPRINT-CREATE: The "Create Blueprint" button is enabled only when at least one player-placeable building (i.e. a building with a button in the build button grid) is currently selected; non-player-placeable buildings (HQ, defence stations) in the selection do not count toward this condition. A selected player-placeable building may be either an operational building or a construction site (a building placed but not yet fully built, REQ-BLD-SITE-CONFIG); both count toward this condition and are captured identically (REQ-UI-BLUEPRINT-STORAGE). When clicked, a modal dialog appears prompting the player to enter a name. The dialog has Confirm and Cancel buttons. Clicking Cancel closes the dialog with no effect. Clicking Confirm with a non-empty name creates a blueprint from the current selection, silently excluding any non-player-placeable buildings, and appends its button to the blueprint list.
 
-- REQ-UI-BLUEPRINT-STORAGE: A blueprint stores its name and, for each building in the selection, the building type, its rotation, its tile offset (integer dx, dy) from the center of the bounding box of all selected buildings' footprints, and — where applicable — the selected recipe ID (miners and assemblers) or schematic ID (shipyards), and for splitters the two output filters (each a list of item types; an empty list means accept-all), at the time of capture. If no recipe or schematic was selected at capture time, none is stored; for a splitter with no filters set, no filter lists are stored. This structure maps directly to a TOML representation (e.g. one `[[building]]` array entry per constituent building, with the splitter filters as `filter_a`/`filter_b` arrays of item-type ids).
+- REQ-UI-BLUEPRINT-TEMP: Pressing the **T** key (REQ-UI-HOTKEYS) creates a **temporary blueprint** from the current selection and immediately enters blueprint placement mode for it, without opening the naming dialog. It has effect only when at least one player-placeable building is currently selected — the same condition as REQ-UI-BLUEPRINT-CREATE; pressing T with an empty selection, or a selection containing only non-player-placeable buildings (HQ, defence stations), does nothing. Entering this mode replaces any currently active build, blueprint placement, or demolish mode. The temporary blueprint is captured exactly as a saved blueprint (REQ-UI-BLUEPRINT-STORAGE), silently excluding any non-player-placeable buildings from the selection, but it is never named, never shown in the blueprint panel (REQ-UI-BLUEPRINT-PANEL), and never persisted to `blueprints.toml` (REQ-UI-BLUEPRINT-SAVE). Placement behaves identically to a saved blueprint's placement mode (REQ-UI-BLUEPRINT-MODE, REQ-UI-BLUEPRINT-PLACE): a ghost is rendered per building, R / Shift+R rotate the entire constellation, placement follows the same per-building validity and total-cost rules, and after a successful placement the mode stays active so the blueprint can be placed again. Right-clicking in the game world exits placement mode, at which point the temporary blueprint is discarded.
+
+- REQ-UI-BLUEPRINT-STORAGE: A blueprint stores its name and, for each building in the selection, the building type, its rotation, its tile offset (integer dx, dy) from the center of the bounding box of all selected buildings' footprints, and — where applicable — the selected recipe ID (miners and assemblers) or schematic ID (shipyards), and for splitters the two output filters (each a list of item types; an empty list means accept-all), at the time of capture. A source building may be either an operational building or a construction site (REQ-BLD-SITE-CONFIG); a construction site is captured identically, storing whatever configuration it currently holds and never any buffer or construction-progress state. If no recipe or schematic was selected at capture time, none is stored; for a splitter with no filters set, no filter lists are stored. This structure maps directly to a TOML representation (e.g. one `[[building]]` array entry per constituent building, with the splitter filters as `filter_a`/`filter_b` arrays of item-type ids).
 
 - REQ-UI-BLUEPRINT-BUTTON: Each blueprint entry consists of a blueprint button and a dedicated delete icon ("×") placed to the right of the button. The blueprint button displays the blueprint name and, below it, the total building block cost of the blueprint (sum of the individual costs of all constituent buildings). A blueprint button is disabled when the player cannot afford the total cost. Clicking an enabled blueprint button enters blueprint placement mode for that blueprint. The delete icon is always enabled regardless of whether the player can afford the blueprint.
 
@@ -470,9 +530,9 @@ The screen is divided into two columns: a main column (75% width) containing the
 
 - REQ-UI-BLUEPRINT-DELETE: Clicking the delete icon ("×") on a blueprint entry immediately removes that blueprint from the list. If the deleted blueprint was active in blueprint placement mode, that mode is exited.
 
-- REQ-UI-BLUEPRINT-SAVE: A "Save" button is shown at the bottom of the blueprint panel. Clicking it serializes all current blueprints to a file named `blueprints.toml` located in the same directory as the application executable. The TOML structure matches REQ-UI-BLUEPRINT-STORAGE. If writing fails, a modal error dialog is shown describing the failure.
+- REQ-UI-BLUEPRINT-SAVE: On application shutdown, all current blueprints are serialized to a file named `blueprints.toml` located in the same directory as the application executable. The TOML structure matches REQ-UI-BLUEPRINT-STORAGE. Write errors are silently ignored on shutdown (no button, no dialog).
 
-- REQ-UI-BLUEPRINT-LOAD: A "Load" button is shown at the bottom of the blueprint panel, to the right of the "Save" button. Clicking it shows a confirmation dialog ("Load blueprints? This will replace all current blueprints.") with Confirm and Cancel buttons. Clicking Cancel closes the dialog with no effect. Clicking Confirm reads `blueprints.toml` from the same directory as the application executable, replaces all current blueprints with those from the file (in the order they appear in the file), and exits any active blueprint-related mode (blueprint placement mode, delete mode). If the file does not exist or cannot be parsed, a modal error dialog is shown describing the failure and the current blueprint list is left unchanged.
+- REQ-UI-BLUEPRINT-LOAD: At application startup, blueprints are loaded from `blueprints.toml` in the same directory as the application executable, populating the blueprint list (in the order they appear in the file). If the file does not exist, the blueprint list starts empty with no error. If the file exists but cannot be parsed (malformed TOML), a modal error dialog describes the failure and the blueprint list starts empty. There is no Load button and no runtime reload.
 
 ## Balancing Tool
 
@@ -506,13 +566,17 @@ A separate executable target (`balancing`) that links against `lib` but contains
 
 ### UI
 
-- REQ-BAL-UI-WINDOW: On startup the tool displays a window containing a "Reload Config" button and a "Start All" button at the top (in that order, left to right), followed by a scrollable vertical list of arena widgets, one per arena defined in `balancing.toml`. Simulations do not start automatically on startup. All buttons and controls in the main window are disabled while an arena is being inspected (REQ-BAL-UI-INSPECT).
+- REQ-BAL-UI-WINDOW: On startup the tool displays a window containing a "Reload Config" button, a "Start All" button, and a "Log" button at the top (in that order, left to right), followed by a scrollable vertical list of arena widgets, one per arena defined in `balancing.toml`. Simulations do not start automatically on startup. All buttons and controls in the main window are disabled while an arena is being inspected (REQ-BAL-UI-INSPECT).
 - REQ-BAL-UI-RELOAD: The "Reload Config" button reloads all config files from disk (`balancing.toml`, `ships.toml`, `stations.toml`), stops any running simulations, and replaces the arena widget list with freshly created widgets from the reloaded config. The button is disabled while any arena simulation is currently running.
 - REQ-BAL-UI-START-ALL: The "Start All" button is placed above the scrollable arena list, to the right of the "Reload Config" button. Clicking it starts (or restarts) the simulation for every arena that is not currently running. The button is disabled when all arenas are currently running.
-- REQ-BAL-UI-WIDGET: Each arena widget displays the arena name, an "Inspect" button (to the right of the arena name), and two columns (one per team). Each column shows the team name as a header, then directly below the header the team's **accumulated threat level** — the sum, across the team's configured ship entries, of each entry's `count` multiplied by the threat cost (REQ-MOD-THREAT) of one ship of that entry computed from its level-independent module layout. Only ships contribute; the HQ and defence stations are excluded. This value is static: it is computed once from the full configured roster and does not change as ships are destroyed during the fight. Below the threat level, the column shows a list of entries. The HQ is always the first entry in each column. Below the HQ, ship types are listed, followed by defence stations (if any). Each entry uses the format `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries — for example `2/3 Fighter`, `1/1 HQ L1`, or `2/2 Enemy Station L3`. The surviving count updates live as the simulation progresses. When the fight ends, the winning team's name header is prefixed with `[WON]`.
+- REQ-BAL-UI-LOG: The "Log" button is placed in the header to the right of the "Start All" button. It is enabled whenever the main window's controls are enabled — including while simulations are running (it captures a live snapshot) — and, like all main window controls, is disabled only while an arena is being inspected (REQ-BAL-UI-WINDOW). Clicking it writes the current state of every arena to a file named `balancing_log.md` in the tool's current working directory, replacing (overwriting) any previous content of that file. The log captures, for every arena in `balancing.toml` order, exactly the information shown in that arena's widget (REQ-BAL-UI-WIDGET) at the moment the button is clicked. Each arena is written as its own section:
+  - A heading with the arena name followed by the arena's current state — `not started`, `running`, or `ended` (corresponding to the widget border colors of REQ-BAL-UI-WIDGET-BORDER). For an `ended` arena, the heading also includes the battle duration (REQ-BAL-UI-WIDGET), for example `ended, 42.3 s`.
+  - A markdown table with one column per team (team 1 left, team 2 right). Each team's column header shows the team name — prefixed with `[WON]` when that team won, matching REQ-BAL-UI-WIDGET — the team's accumulated threat level, and the team's remaining EHP percentage (REQ-BAL-UI-WIDGET).
+  - Below the header, each table row holds one of that team's entries, in the same order and text format as the widget (REQ-BAL-UI-WIDGET): the HQ first, then ship types, then defence stations, formatted `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries. When the two teams have different numbers of entries, the shorter column's remaining cells are left blank.
+- REQ-BAL-UI-WIDGET: Each arena widget displays the arena name, an "Inspect" button (to the right of the arena name), and two columns (one per team). Each column shows the team name as a header, then directly below the header the team's **accumulated threat level** — the sum, across the team's configured ship entries, of each entry's `count` multiplied by the threat cost (REQ-MOD-THREAT) of one ship of that entry computed from its level-independent module layout. Only ships contribute; the HQ and defence stations are excluded. This value is static: it is computed once from the full configured roster and does not change as ships are destroyed during the fight. Directly below the threat level, the column shows the team's **remaining EHP percentage** — the sum of the current HP of all of the team's ships and defence stations, divided by the sum of their maximum HP, expressed as a percentage rounded to a whole number. Maximum HP is the final per-entity maximum (REQ-MOD-STAT-CALC), so module HP bonuses such as armor plates are included. (The game has no damage mitigation, so effective HP equals raw HP.) The HQ is excluded from both sums. A destroyed ship or station contributes 0 to the numerator and its maximum HP to the denominator, so the value measures how much of the team's fielded durability remains: it starts at 100% and decreases as units take damage or are destroyed. Unlike the static threat level, this value updates live as the simulation progresses. If the team has neither ships nor defence stations (the denominator is 0), the percentage is shown as `n/a`. Below the EHP percentage, the column shows a list of entries. The HQ is always the first entry in each column. Below the HQ, ship types are listed, followed by defence stations (if any). Each entry uses the format `surviving/total TypeName` for ship entries and `surviving/total TypeName Llevel` for the HQ and defence station entries — for example `2/3 Fighter`, `1/1 HQ L1`, or `2/2 Enemy Station L3`. The surviving count updates live as the simulation progresses. When the fight ends, the winning team's name header is prefixed with `[WON]`. When the fight has ended, the widget also displays the arena's **battle duration** — an arena-level value (not per team) giving the game time the fight lasted, computed as the number of simulated ticks at completion multiplied by the simulation's fixed tick duration (the same tick-based simulation as the main game, REQ-BAL-SIM-ENV). This is game time, not wall-clock time, so it is independent of how fast the arena was simulated (non-inspected arenas run at maximum tick rate, REQ-BAL-SIM-SPEED). It is shown in seconds with one decimal place, for example `Duration: 42.3 s`. The battle duration is shown only for completed (ended) runs; it is not shown while the arena is not started or running.
 - REQ-BAL-UI-WIDGET-START: Each arena widget contains a "Start" button that starts the simulation for that arena. The button is disabled while the arena's simulation is running. When a finished arena's Start button is clicked, a fresh simulation is created and started (the widget resets to initial unit counts, the border returns to blue, and the previous results are replaced).
 - REQ-BAL-UI-WIDGET-BORDER: Each arena widget has a colored border indicating its state: grey when not yet started, blue while its simulation is running, and green when the fight has ended.
 - REQ-BAL-UI-INSPECT: Clicking an arena widget's "Inspect" button opens a new inspect window for that arena. Any previously open inspect window is closed first (its arena's simulation is aborted and its widget border returns to grey). The inspected arena is restarted with a fresh simulation that runs at controllable game speed with full rendering (REQ-BAL-SIM-SPEED). The arena widget updates live during inspection (surviving counts, border color, `[WON]` prefix) as it does for non-inspected arenas. Only one inspect window may be open at a time.
-- REQ-BAL-UI-INSPECT-WINDOW: The inspect window consists of three sections, top to bottom: a title bar area containing the arena name and game speed controls (same buttons as the main game: 0×, 0.5×, 1×, 2×, 4×, with Space to toggle pause — see REQ-UI-SPEED and REQ-UI-HOTKEYS), the arena view in the center, and an info panel at the bottom displaying the same team columns and entry format as the arena widget in the main window (REQ-BAL-UI-WIDGET), updated live.
+- REQ-BAL-UI-INSPECT-WINDOW: The inspect window consists of three sections, top to bottom: a title bar area containing the arena name and game speed controls (same buttons as the main game: 0×, 0.5×, 1×, 2×, 4×, with Space to toggle pause — see REQ-UI-SPEED and REQ-UI-HOTKEYS), the arena view in the center, and an info panel at the bottom displaying the same team columns and entry format as the arena widget in the main window (REQ-BAL-UI-WIDGET), updated live, including the arena's battle duration once the fight has ended (REQ-BAL-UI-WIDGET).
 - REQ-BAL-UI-INSPECT-VIEW: The arena view renders all tiles of the arena and displays ships, HQs, defence stations, and laser beams using the same visual elements and `visuals.toml` colors as the main game. Team 1 uses player visual styles; team 2 uses enemy visual styles. The view has a fixed zoom level — no zoom or scroll is possible. The tile size is derived so that the full arena (all tiles) fits within the view.
 - REQ-BAL-UI-INSPECT-CLOSE: Closing the inspect window (via the window's close button) aborts the inspected arena's simulation. The arena widget's border returns to grey and its surviving counts are left as they were at the moment of closing. All main window buttons and controls are re-enabled.

src/CMakeLists.txt

@@ -1,4 +1,4 @@
-set(TARGET_BASE_NAME "DotaFactory")
+set(TARGET_BASE_NAME "${PRODUCT_NAME}")
 
 set(TARGET_APP_NAME "${TARGET_BASE_NAME}")
 set(TARGET_LIB_NAME "${TARGET_BASE_NAME}_lib")
@@ -183,6 +183,19 @@ target_compile_definitions(${TARGET_APP_NAME} PRIVATE
 )
 target_link_libraries(${TARGET_APP_NAME} ${TARGET_UI_NAME})
 
+# Embed the Windows version resource so the version shows on the executable's
+# Details tab (right-click -> Properties). Values come from cmake/version.cmake
+# (version numbers) and the product identity variables in the top-level
+# CMakeLists.txt. MSVC compiles the .rc automatically once it is a target source.
+if (WIN32)
+    configure_file(
+        "${CMAKE_SOURCE_DIR}/cmake/version.rc.in"
+        "${CMAKE_CURRENT_BINARY_DIR}/version.rc"
+        @ONLY
+    )
+    target_sources(${TARGET_APP_NAME} PRIVATE "${CMAKE_CURRENT_BINARY_DIR}/version.rc")
+endif ()
+
 unset(APP_FILES)
 unset(RELATIVE_HDRS)
 unset(RELATIVE_SRCS)

src/balancing/ArenaSimulation.cpp

@@ -2,6 +2,8 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cmath>
+#include <string>
 
 #include <QVector2D>
 
@@ -86,12 +88,49 @@ ArenaSimulation::ArenaSimulation(const GameConfig& gameConfig,
 
     placeStructures();
     spawnShips();
+    computeTeamMaxEhp();
 
     m_shipSystem->triggerRallyDeparture();
 
     updateStatus();
 }
 
+std::string ArenaStatus::TeamStatus::ehpPercentText() const
+{
+    if (maxEhp <= 0.0)
+    {
+        return "n/a";
+    }
+    const int percent = static_cast<int>(std::lround(100.0 * currentEhp / maxEhp));
+    return std::to_string(percent) + "%";
+}
+
+void ArenaSimulation::computeTeamMaxEhp()
+{
+    m_teamMaxEhp[0] = 0.0;
+    m_teamMaxEhp[1] = 0.0;
+
+    // Ships contribute their full max HP.
+    m_admin.forEach<ShipIdentityComponent, FactionComponent, HealthComponent>(
+        [this](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
+               const FactionComponent& f, const HealthComponent& h)
+        {
+            m_teamMaxEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.maxHp);
+        });
+
+    // Defence stations contribute their full max HP; the HQ is excluded.
+    m_admin.forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+        [this](entt::entity e, const StationBodyComponent& /*sb*/,
+               const FactionComponent& f, const HealthComponent& h)
+        {
+            if (m_admin.hasAll<HqProxyComponent>(e))
+            {
+                return;
+            }
+            m_teamMaxEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.maxHp);
+        });
+}
+
 ArenaSimulation::~ArenaSimulation() = default;
 
 BuildingId ArenaSimulation::allocateBuildingId()
@@ -394,10 +433,13 @@ void ArenaSimulation::tickDeaths()
         });
 
     m_admin.forEach<StationBodyComponent, FactionComponent>(
-        [&team1HasUnits, &team2HasUnits](entt::entity /*e*/,
+        [this, &team1HasUnits, &team2HasUnits](entt::entity e,
                                           const StationBodyComponent& /*sb*/,
                                           const FactionComponent& f)
         {
+            // The HQ carries a StationBodyComponent but is not a defence station;
+            // its destruction is a separate end condition (REQ-BAL-SIM-END).
+            if (m_admin.hasAll<HqProxyComponent>(e)) { return; }
             if (f.isEnemy) { team2HasUnits = true; }
             else           { team1HasUnits = true; }
         });
@@ -476,12 +518,41 @@ void ArenaSimulation::updateStatus()
     ArenaStatus newStatus;
     newStatus.finished = m_finished;
     newStatus.winnerTeam = m_winnerTeam;
+    newStatus.durationSeconds = ticksToSeconds(m_currentTick);
+
+    // Live remaining HP of each team's ships and defence stations (HQ excluded);
+    // the EHP-percentage numerator (denominator is the fixed m_teamMaxEhp).
+    double currentEhp[2] = {0.0, 0.0};
+    m_admin.forEach<ShipIdentityComponent, FactionComponent, HealthComponent>(
+        [&currentEhp](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
+                      const FactionComponent& f, const HealthComponent& h)
+        {
+            if (h.hp > 0.0f)
+            {
+                currentEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.hp);
+            }
+        });
+    m_admin.forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+        [this, &currentEhp](entt::entity e, const StationBodyComponent& /*sb*/,
+                            const FactionComponent& f, const HealthComponent& h)
+        {
+            if (m_admin.hasAll<HqProxyComponent>(e))
+            {
+                return;
+            }
+            if (h.hp > 0.0f)
+            {
+                currentEhp[f.isEnemy ? 1 : 0] += static_cast<double>(h.hp);
+            }
+        });
 
     for (int ti = 0; ti < 2; ++ti)
     {
         ArenaStatus::TeamStatus& teamStatus = newStatus.teams[ti];
         teamStatus.name = m_arenaConfig.teams[ti].name;
         teamStatus.threatLevel = m_teamThreat[ti];
+        teamStatus.currentEhp = currentEhp[ti];
+        teamStatus.maxEhp = m_teamMaxEhp[ti];
 
         // HQ entry (always first).
         {

src/balancing/ArenaSimulation.h

@@ -44,12 +44,24 @@ struct ArenaStatus
     {
         std::string name;
         double threatLevel = 0.0;    // accumulated threat of the team's configured ships
+        // Remaining durability of the team's ships and defence stations (HQ
+        // excluded). currentEhp is summed live; maxEhp is the fixed full-HP
+        // baseline. See ehpPercentText() for the displayed value.
+        double currentEhp = 0.0;
+        double maxEhp = 0.0;
         std::vector<Entry> entries;  // HQ first, then ships, then stations
+
+        // Remaining EHP as a whole-number percentage ("NN%"), or "n/a" when the
+        // team has no ships or stations (maxEhp == 0).
+        std::string ehpPercentText() const;
     };
 
     TeamStatus teams[2];
     bool finished = false;
     int winnerTeam = -1;  // 0 or 1 when finished; -1 while running
+    // Game time the fight has lasted (simulated ticks * fixed tick duration).
+    // Meaningful once finished; the battle duration shown for completed runs.
+    double durationSeconds = 0.0;
 };
 
 class ArenaSimulation
@@ -82,6 +94,7 @@ private:
     BuildingId allocateBuildingId();
     void placeStructures();
     void spawnShips();
+    void computeTeamMaxEhp();
     void tick();
     void tickDeaths();
     void updateStatus();
@@ -115,6 +128,10 @@ private:
     // Static accumulated threat per team, computed once from the configured roster.
     double m_teamThreat[2] = {0.0, 0.0};
 
+    // Full-HP baseline per team (ships + defence stations, HQ excluded), computed
+    // once after spawning; the EHP-percentage denominator.
+    double m_teamMaxEhp[2] = {0.0, 0.0};
+
     std::vector<BeamFiredEvent> m_beamFiredEvents;
 
     mutable std::mutex m_statusMutex;

src/balancing/ArenaWidget.cpp

@@ -33,6 +33,9 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     m_titleLabel->setFont(titleFont);
     titleRow->addWidget(m_titleLabel);
 
+    m_durationLabel = new QLabel(this);
+    titleRow->addWidget(m_durationLabel);
+
     titleRow->addStretch();
 
     m_inspectButton = new QPushButton(tr("Inspect"), this);
@@ -63,6 +66,8 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     team1Layout->addWidget(m_team1Header);
     m_team1Threat = new QLabel(this);
     team1Layout->addWidget(m_team1Threat);
+    m_team1Ehp = new QLabel(this);
+    team1Layout->addWidget(m_team1Ehp);
     m_team1Content = new QLabel(this);
     team1Layout->addWidget(m_team1Content);
     team1Layout->addStretch();
@@ -75,6 +80,8 @@ void ArenaWidget::buildLayout(const std::string& arenaName)
     team2Layout->addWidget(m_team2Header);
     m_team2Threat = new QLabel(this);
     team2Layout->addWidget(m_team2Threat);
+    m_team2Ehp = new QLabel(this);
+    team2Layout->addWidget(m_team2Ehp);
     m_team2Content = new QLabel(this);
     team2Layout->addWidget(m_team2Content);
     team2Layout->addStretch();
@@ -99,13 +106,29 @@ void ArenaWidget::resetToGrey()
     setStyleSheet("ArenaWidget { border: 2px solid #999999; padding: 8px; }");
 }
 
+ArenaWidget::State ArenaWidget::getState() const
+{
+    if (m_wasFinished)
+    {
+        return State::Ended;
+    }
+    if (m_running)
+    {
+        return State::Running;
+    }
+    return State::NotStarted;
+}
+
 void ArenaWidget::updateStatus(const ArenaStatus& status)
 {
+    m_lastStatus = status;
+
     for (int ti = 0; ti < 2; ++ti)
     {
         const ArenaStatus::TeamStatus& team = status.teams[ti];
         QLabel* header = (ti == 0) ? m_team1Header : m_team2Header;
         QLabel* threat = (ti == 0) ? m_team1Threat : m_team2Threat;
+        QLabel* ehp = (ti == 0) ? m_team1Ehp : m_team2Ehp;
         QLabel* content = (ti == 0) ? m_team1Content : m_team2Content;
 
         if (status.finished && status.winnerTeam == ti)
@@ -118,6 +141,7 @@ void ArenaWidget::updateStatus(const ArenaStatus& status)
         }
 
         threat->setText(tr("Threat: %1").arg(QString::number(team.threatLevel, 'f', 0)));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.ehpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)
@@ -138,6 +162,10 @@ void ArenaWidget::updateStatus(const ArenaStatus& status)
         content->setText(lines);
     }
 
+    m_durationLabel->setText(status.finished
+        ? tr("Duration: %1 s").arg(QString::number(status.durationSeconds, 'f', 1))
+        : QString());
+
     if (status.finished && !m_wasFinished)
     {
         m_wasFinished = true;

src/balancing/ArenaWidget.h

@@ -14,21 +14,35 @@ class ArenaWidget : public QFrame
     Q_OBJECT
 
 public:
+    enum class State
+    {
+        NotStarted,
+        Running,
+        Ended
+    };
+
     ArenaWidget(int arenaIndex, const std::string& arenaName, QWidget* parent = nullptr);
 
     void updateStatus(const ArenaStatus& status);
     void startSimulation();
     void resetToGrey();
 
+    const ArenaStatus& getLastStatus() const { return m_lastStatus; }
+    State getState() const;
+
 private:
     void buildLayout(const std::string& arenaName);
 
     int m_arenaIndex;
+    ArenaStatus m_lastStatus;
     QLabel* m_titleLabel;
+    QLabel* m_durationLabel;
     QLabel* m_team1Header;
     QLabel* m_team2Header;
     QLabel* m_team1Threat;
     QLabel* m_team2Threat;
+    QLabel* m_team1Ehp;
+    QLabel* m_team2Ehp;
     QLabel* m_team1Content;
     QLabel* m_team2Content;
     QPushButton* m_inspectButton;

src/balancing/BalancingWindow.cpp

@@ -1,13 +1,70 @@
 #include "BalancingWindow.h"
 
+#include <algorithm>
+
+#include <QFile>
 #include <QHBoxLayout>
 #include <QMessageBox>
+#include <QTextStream>
 #include <QVBoxLayout>
 
 #include "ConfigLoader.h"
 #include "InspectWindow.h"
 #include "VisualsLoader.h"
 
+namespace
+{
+    // Escapes characters that would break a markdown table cell.
+    QString escapeCell(const QString& text)
+    {
+        QString escaped = text;
+        escaped.replace("|", "\\|");
+        return escaped;
+    }
+
+    QString stateText(ArenaWidget::State state)
+    {
+        switch (state)
+        {
+            case ArenaWidget::State::NotStarted:
+                return QStringLiteral("not started");
+            case ArenaWidget::State::Running:
+                return QStringLiteral("running");
+            case ArenaWidget::State::Ended:
+                return QStringLiteral("ended");
+        }
+        return QString();
+    }
+
+    // Team column header: "[WON] Name — threat N", matching the arena widget.
+    QString teamHeaderCell(const ArenaStatus& status, int teamIndex)
+    {
+        const ArenaStatus::TeamStatus& team = status.teams[teamIndex];
+        QString header = QString::fromStdString(team.name);
+        if (status.finished && status.winnerTeam == teamIndex)
+        {
+            header = QStringLiteral("[WON] ") + header;
+        }
+        header += QStringLiteral(" - threat %1").arg(QString::number(team.threatLevel, 'f', 0));
+        header += QStringLiteral(" - EHP %1").arg(QString::fromStdString(team.ehpPercentText()));
+        return escapeCell(header);
+    }
+
+    // Single entry line: "surviving/total DisplayName [L<level>]", matching the arena widget.
+    QString entryCell(const ArenaStatus::Entry& entry)
+    {
+        QString cell = QString("%1/%2 %3")
+                           .arg(entry.surviving)
+                           .arg(entry.total)
+                           .arg(QString::fromStdString(entry.displayName));
+        if (entry.level.has_value())
+        {
+            cell += QStringLiteral(" L%1").arg(entry.level.value());
+        }
+        return escapeCell(cell);
+    }
+}
+
 BalancingWindow::BalancingWindow(const BalancingConfig& balancingConfig,
                                  GameConfig gameConfig,
                                  const std::string& configDir,
@@ -31,13 +88,16 @@ BalancingWindow::BalancingWindow(const BalancingConfig& balancingConfig,
     QHBoxLayout* buttonRow = new QHBoxLayout();
     m_reloadButton = new QPushButton(tr("Reload Config"), this);
     m_startAllButton = new QPushButton(tr("Start All"), this);
+    m_logButton = new QPushButton(tr("Log"), this);
     buttonRow->addWidget(m_reloadButton);
     buttonRow->addWidget(m_startAllButton);
+    buttonRow->addWidget(m_logButton);
     buttonRow->addStretch();
     mainLayout->addLayout(buttonRow);
 
     connect(m_reloadButton, &QPushButton::clicked, this, &BalancingWindow::reloadConfig);
     connect(m_startAllButton, &QPushButton::clicked, this, &BalancingWindow::startAll);
+    connect(m_logButton, &QPushButton::clicked, this, &BalancingWindow::writeLog);
 
     m_scrollArea = new QScrollArea(this);
     m_scrollArea->setWidgetResizable(true);
@@ -255,6 +315,7 @@ void BalancingWindow::setMainControlsEnabled(bool enabled)
 {
     m_reloadButton->setEnabled(enabled);
     m_startAllButton->setEnabled(enabled);
+    m_logButton->setEnabled(enabled);
     for (ArenaEntry& entry : m_arenas)
     {
         for (QPushButton* btn : entry.widget->findChildren<QPushButton*>())
@@ -291,4 +352,58 @@ void BalancingWindow::updateButtons()
 
     m_reloadButton->setEnabled(!anyRunning);
     m_startAllButton->setEnabled(!allRunning);
+    m_logButton->setEnabled(true);
+}
+
+void BalancingWindow::writeLog()
+{
+    QFile file(QStringLiteral("balancing_log.md"));
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate | QIODevice::Text))
+    {
+        QMessageBox::warning(this, tr("Log Failed"),
+            tr("Could not open balancing_log.md for writing."));
+        return;
+    }
+
+    QTextStream out(&file);
+    out.setCodec("UTF-8");
+
+    out << "# Balancing Log\n";
+
+    for (const ArenaEntry& entry : m_arenas)
+    {
+        const ArenaStatus& status = entry.widget->getLastStatus();
+        const ArenaWidget::State state = entry.widget->getState();
+
+        QString stateSuffix = stateText(state);
+        if (state == ArenaWidget::State::Ended)
+        {
+            stateSuffix += QStringLiteral(", %1 s")
+                .arg(QString::number(status.durationSeconds, 'f', 1));
+        }
+
+        out << "\n## Arena: " << QString::fromStdString(entry.config.name)
+            << "  (" << stateSuffix << ")\n\n";
+
+        out << "| " << teamHeaderCell(status, 0) << " | "
+            << teamHeaderCell(status, 1) << " |\n";
+        out << "|---|---|\n";
+
+        const std::size_t rowCount = std::max(status.teams[0].entries.size(),
+                                              status.teams[1].entries.size());
+        for (std::size_t row = 0; row < rowCount; ++row)
+        {
+            QString leftCell;
+            if (row < status.teams[0].entries.size())
+            {
+                leftCell = entryCell(status.teams[0].entries[row]);
+            }
+            QString rightCell;
+            if (row < status.teams[1].entries.size())
+            {
+                rightCell = entryCell(status.teams[1].entries[row]);
+            }
+            out << "| " << leftCell << " | " << rightCell << " |\n";
+        }
+    }
 }

src/balancing/BalancingWindow.h

@@ -46,6 +46,7 @@ private slots:
     void pollStatuses();
     void reloadConfig();
     void startAll();
+    void writeLog();
 
 private:
     void startArena(int index);
@@ -72,6 +73,7 @@ private:
     unsigned int m_nextSeed;
     QPushButton* m_reloadButton;
     QPushButton* m_startAllButton;
+    QPushButton* m_logButton;
     QScrollArea* m_scrollArea;
     QTimer* m_pollTimer;
 

src/balancing/InspectWindow.cpp

@@ -14,6 +14,7 @@
 #include "HealthComponent.h"
 #include "InspectWindowClosedEvent.h"
 #include "ModuleOwnerComponent.h"
+#include "SelectedBehaviorComponent.h"
 #include "ShipIdentityComponent.h"
 #include "ShipStatsCalculator.h"
 #include "ShipStatsPanel.h"
@@ -52,6 +53,9 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         nameLabel->setFont(nameFont);
         headerLayout->addWidget(nameLabel);
 
+        m_durationLabel = new QLabel(header);
+        headerLayout->addWidget(m_durationLabel);
+
         headerLayout->addStretch();
 
         const char* labels[] = { "0x", "0.5x", "1x", "2x", "10x" };
@@ -93,6 +97,8 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         team1Layout->addWidget(m_team1Header);
         m_team1Threat = new QLabel(infoPanel);
         team1Layout->addWidget(m_team1Threat);
+        m_team1Ehp = new QLabel(infoPanel);
+        team1Layout->addWidget(m_team1Ehp);
         m_team1Content = new QLabel(infoPanel);
         team1Layout->addWidget(m_team1Content);
         team1Layout->addStretch();
@@ -104,6 +110,8 @@ InspectWindow::InspectWindow(ArenaSimulation* sim, const GameConfig* config,
         team2Layout->addWidget(m_team2Header);
         m_team2Threat = new QLabel(infoPanel);
         team2Layout->addWidget(m_team2Threat);
+        m_team2Ehp = new QLabel(infoPanel);
+        team2Layout->addWidget(m_team2Ehp);
         m_team2Content = new QLabel(infoPanel);
         team2Layout->addWidget(m_team2Content);
         team2Layout->addStretch();
@@ -198,11 +206,16 @@ void InspectWindow::pollStatus()
 
 void InspectWindow::updateInfoPanel(const ArenaStatus& status)
 {
+    m_durationLabel->setText(status.finished
+        ? tr("Duration: %1 s").arg(QString::number(status.durationSeconds, 'f', 1))
+        : QString());
+
     for (int ti = 0; ti < 2; ++ti)
     {
         const ArenaStatus::TeamStatus& team = status.teams[ti];
         QLabel* header  = (ti == 0) ? m_team1Header  : m_team2Header;
         QLabel* threat  = (ti == 0) ? m_team1Threat  : m_team2Threat;
+        QLabel* ehp     = (ti == 0) ? m_team1Ehp     : m_team2Ehp;
         QLabel* content = (ti == 0) ? m_team1Content  : m_team2Content;
 
         if (status.finished && status.winnerTeam == ti)
@@ -215,6 +228,7 @@ void InspectWindow::updateInfoPanel(const ArenaStatus& status)
         }
 
         threat->setText(tr("Threat: %1").arg(QString::number(team.threatLevel, 'f', 0)));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.ehpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)
@@ -265,6 +279,8 @@ void InspectWindow::handleEvent(std::shared_ptr<const EntitySelectedEvent> event
 
             const ShipStats stats = buildShipStatsFromEntity(admin, entity);
             m_entityStatsPanel->refreshFromLive(stats, health.hp);
+            m_entityStatsPanel->setBehavior(
+                admin.get<SelectedBehaviorComponent>(entity).winner);
             m_entityStatsPanel->show();
             m_stationStatsLabel->hide();
         }
@@ -342,6 +358,8 @@ void InspectWindow::refreshEntityStats()
     {
         const ShipStats stats = buildShipStatsFromEntity(admin, entity);
         m_entityStatsPanel->refreshFromLive(stats, health.hp);
+        m_entityStatsPanel->setBehavior(
+            admin.get<SelectedBehaviorComponent>(entity).winner);
     }
     else if (admin.hasAll<StationBodyComponent>(entity))
     {

src/balancing/InspectWindow.h

@@ -54,10 +54,13 @@ private:
     ArenaView*         m_arenaView;
 
     std::vector<QPushButton*> m_speedButtons;
+    QLabel* m_durationLabel;
     QLabel* m_team1Header;
     QLabel* m_team2Header;
     QLabel* m_team1Threat;
     QLabel* m_team2Threat;
+    QLabel* m_team1Ehp;
+    QLabel* m_team2Ehp;
     QLabel* m_team1Content;
     QLabel* m_team2Content;
     QTimer* m_pollTimer;

src/lib/config/BuildingsConfig.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -18,9 +19,30 @@ struct BuildingDef
     // Stored as raw strings here; parsing into per-cell tiles + output ports
     // happens when buildings are placed, not at load time.
     std::vector<std::string> surfaceMask;
+
+    // Output-buffer holding size for buildings without a recipe-driven buffer.
+    // Only the Salvage Bay sets this (REQ-BLD-SALVAGE-BAY).
+    std::optional<int> outputBufferCapacity;
+
+    // Optional hover-tooltip text for the build button (REQ-UI-BUILD-TOOLTIP).
+    std::optional<std::string> tooltip;
 };
 
 struct BuildingsConfig
 {
     std::vector<BuildingDef> buildings;
+
+    // Returns the definition for the given building type, or nullptr if the
+    // type has no entry in buildings.toml.
+    const BuildingDef* findBuildingDef(BuildingType type) const
+    {
+        for (const BuildingDef& def : buildings)
+        {
+            if (def.type == type)
+            {
+                return &def;
+            }
+        }
+        return nullptr;
+    }
 };

src/lib/config/ConfigLoader.cpp

@@ -4,6 +4,7 @@
 #include <sstream>
 #include <stdexcept>
 #include <string>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -272,13 +273,19 @@ WorldConfig ConfigLoader::loadWorld(const std::string& path)
     cfg.orbitFactor                = requireDouble(tbl["world"]["orbit_factor"], file, "world.orbit_factor");
     cfg.rallyOrbitRadius_tiles     = requireDouble(tbl["world"]["rally_orbit_radius_tiles"], file, "world.rally_orbit_radius_tiles");
 
+    if (const std::optional<std::string> tip =
+            tbl["world"]["building_blocks_tooltip"].value<std::string>())
+    {
+        cfg.buildingBlocksTooltip = *tip;
+    }
+
     cfg.regions.asteroidWidth_tiles     = static_cast<int>(requireInt(tbl["regions"]["asteroid_width_tiles"],      file, "regions.asteroid_width_tiles"));
     cfg.regions.playerBufferWidth_tiles = static_cast<int>(requireInt(tbl["regions"]["player_buffer_width_tiles"], file, "regions.player_buffer_width_tiles"));
     cfg.regions.contestZoneWidth_tiles  = static_cast<int>(requireInt(tbl["regions"]["contest_zone_width_tiles"],  file, "regions.contest_zone_width_tiles"));
     cfg.regions.enemyBufferWidth_tiles  = static_cast<int>(requireInt(tbl["regions"]["enemy_buffer_width_tiles"],  file, "regions.enemy_buffer_width_tiles"));
 
-    cfg.expansion.columnsPerExpansion_tiles = static_cast<int>(requireInt(tbl["expansion"]["columns_per_expansion_tiles"], file, "expansion.columns_per_expansion_tiles"));
-    cfg.expansion.costBuildingBlocks        = static_cast<int>(requireInt(tbl["expansion"]["cost_building_blocks"],        file, "expansion.cost_building_blocks"));
+    cfg.expansion.columnsPerExpansion_tiles   = static_cast<int>(requireInt(tbl["expansion"]["columns_per_expansion_tiles"], file, "expansion.columns_per_expansion_tiles"));
+    cfg.expansion.costBuildingBlocksFormula   = requireFormula(tbl["expansion"]["cost_building_blocks_formula"],            file, "expansion.cost_building_blocks_formula");
 
     cfg.push.pushExpandColumns_tiles = static_cast<int>(requireInt(tbl["push"]["push_expand_columns_tiles"], file, "push.push_expand_columns_tiles"));
     cfg.push.bossAdvanceSeconds = requireDouble(tbl["push"]["boss_advance_seconds"], file, "push.boss_advance_seconds");
@@ -304,6 +311,10 @@ WorldConfig ConfigLoader::loadWorld(const std::string& path)
     cfg.artifacts.artifactChanceFormula = requireFormula(tbl["artifacts"]["artifact_chance_formula"], file, "artifacts.artifact_chance_formula");
     cfg.artifacts.artifactWinCount      = static_cast<int>(requireInt(tbl["artifacts"]["artifact_win_count"], file, "artifacts.artifact_win_count"));
 
+    cfg.scroll.panSpeedSlow_tps       = requireDouble(tbl["scroll"]["pan_speed_slow_tiles_per_second"], file, "scroll.pan_speed_slow_tiles_per_second");
+    cfg.scroll.panSpeedFast_tps       = requireDouble(tbl["scroll"]["pan_speed_fast_tiles_per_second"], file, "scroll.pan_speed_fast_tiles_per_second");
+    cfg.scroll.panRampBandWidth_tiles = static_cast<int>(requireInt(tbl["scroll"]["pan_ramp_band_width_tiles"], file, "scroll.pan_ramp_band_width_tiles"));
+
     return cfg;
 }
 
@@ -332,6 +343,17 @@ BuildingsConfig ConfigLoader::loadBuildings(const std::string& path)
         def.constructionTimeSeconds = requireDouble(mt["construction_time_seconds"], file, elemPath + ".construction_time_seconds");
         def.surfaceMask             = requireStringArray(mt["surface_mask"],         file, elemPath + ".surface_mask");
 
+        if (mt.contains("output_buffer_capacity"))
+        {
+            def.outputBufferCapacity = static_cast<int>(
+                requireInt(mt["output_buffer_capacity"], file, elemPath + ".output_buffer_capacity"));
+        }
+
+        if (mt.contains("tooltip"))
+        {
+            def.tooltip = requireString(mt["tooltip"], file, elemPath + ".tooltip");
+        }
+
         const std::optional<BuildingType> parsedType = parseBuildingType(def.id);
         if (!parsedType)
         {
@@ -383,6 +405,11 @@ RecipesConfig ConfigLoader::loadRecipes(const std::string& path)
             {
                 def.unlockAtStationLevel = static_cast<int>(*level);
             }
+            if (mt.contains("unlock_requires"))
+            {
+                def.unlockRequires = requireStringArray(mt["unlock_requires"], file,
+                    elemPath + ".unlock_requires");
+            }
         }
 
         // inputs may be omitted (e.g. miner recipes). An empty array is fine.
@@ -422,6 +449,10 @@ ShipsConfig ConfigLoader::loadShips(const std::string& path)
         ShipDef def;
         def.id                 = requireString(mt["id"],                 file, elemPath + ".id");
         def.unlockAtStationLevel = static_cast<int>(requireInt(mt["unlock_at_station_level"], file, elemPath + ".unlock_at_station_level"));
+        if (mt.contains("unlock_requires"))
+        {
+            def.unlockRequires = requireStringArray(mt["unlock_requires"], file, elemPath + ".unlock_requires");
+        }
         def.layout             = requireStringArray(mt["layout"],       file, elemPath + ".layout");
 
         // Schematic
@@ -573,12 +604,21 @@ ModulesConfig ConfigLoader::loadModules(const std::string& path)
         def.id                      = requireString(mt["id"], file, elemPath + ".id");
         def.unlockAtStationLevel    = static_cast<int>(
             mt["unlock_at_station_level"].value_or<int64_t>(-1));
+        if (mt.contains("unlock_requires"))
+        {
+            def.unlockRequires = requireStringArray(mt["unlock_requires"], file, elemPath + ".unlock_requires");
+        }
         def.surfaceMask             = requireStringArray(mt["surface_mask"], file, elemPath + ".surface_mask");
         def.productionTimeSeconds = requireDouble(
             mt["production_time_seconds"], file, elemPath + ".production_time_seconds");
         def.fillColor             = requireString(mt["fill_color"], file, elemPath + ".fill_color");
         def.glyph                 = requireString(mt["glyph"], file, elemPath + ".glyph");
 
+        if (mt.contains("tooltip"))
+        {
+            def.tooltip = requireString(mt["tooltip"], file, elemPath + ".tooltip");
+        }
+
         // Materials
         {
             const toml::array& materials = requireArray(mt["materials"], file, elemPath + ".materials");
@@ -685,6 +725,67 @@ ModulesConfig ConfigLoader::loadModules(const std::string& path)
     return cfg;
 }
 
+namespace
+{
+
+// Throws if any id in requiredIds is not a valid explicitly-unlockable schematic.
+void checkUnlockRequires(const std::vector<std::string>& requiredIds,
+                         const std::unordered_set<std::string>& schematicIds,
+                         const std::string& file,
+                         const std::string& path)
+{
+    for (const std::string& requiredId : requiredIds)
+    {
+        if (schematicIds.count(requiredId) == 0)
+        {
+            throw makeError(file, path,
+                "references unknown schematic '" + requiredId + "'");
+        }
+    }
+}
+
+// Validates that every id listed in an `unlock_requires` (REQ-LOCK-PREREQ)
+// resolves to an explicitly-unlockable schematic: a ship, a module, or an
+// assembler recipe that carries `unlock_at_station_level` (a recipe schematic,
+// per REQ-LOCK-EXPLICIT). An unresolved id is a config error surfaced at load.
+void validateUnlockRequires(const GameConfig& cfg)
+{
+    std::unordered_set<std::string> schematicIds;
+    for (const ShipDef& def : cfg.ships.ships)
+    {
+        schematicIds.insert(def.id);
+    }
+    for (const ModuleDef& def : cfg.modules.modules)
+    {
+        schematicIds.insert(def.id);
+    }
+    for (const RecipeDef& def : cfg.recipes.recipes)
+    {
+        if (def.building == BuildingType::Assembler && def.unlockAtStationLevel.has_value())
+        {
+            schematicIds.insert(def.id);
+        }
+    }
+
+    for (const ShipDef& def : cfg.ships.ships)
+    {
+        checkUnlockRequires(def.unlockRequires, schematicIds, "ships.toml",
+                            "ship '" + def.id + "'.unlock_requires");
+    }
+    for (const ModuleDef& def : cfg.modules.modules)
+    {
+        checkUnlockRequires(def.unlockRequires, schematicIds, "modules.toml",
+                            "module '" + def.id + "'.unlock_requires");
+    }
+    for (const RecipeDef& def : cfg.recipes.recipes)
+    {
+        checkUnlockRequires(def.unlockRequires, schematicIds, "recipes.toml",
+                            "recipe '" + def.id + "'.unlock_requires");
+    }
+}
+
+} // namespace
+
 GameConfig ConfigLoader::loadFromDirectory(const std::string& configDir)
 {
     GameConfig cfg;
@@ -694,6 +795,7 @@ GameConfig ConfigLoader::loadFromDirectory(const std::string& configDir)
     cfg.ships     = loadShips(configDir + "/ships.toml");
     cfg.stations  = loadStations(configDir + "/stations.toml");
     cfg.modules   = loadModules(configDir + "/modules.toml");
+    validateUnlockRequires(cfg);
     cfg.threatCosts = computeThreatCostTable(cfg);
     return cfg;
 }

src/lib/config/ModulesConfig.h

@@ -41,6 +41,9 @@ struct ModuleDef
 {
     std::string id;
     int unlockAtStationLevel;
+    // Prerequisite schematic ids that must be explicitly unlocked before this
+    // schematic can enter the drop pool (REQ-LOCK-PREREQ). Empty = none.
+    std::vector<std::string> unlockRequires;
     std::vector<std::string> surfaceMask;
     std::vector<RecipeIngredient> materials;
     double productionTimeSeconds;
@@ -51,6 +54,10 @@ struct ModuleDef
     std::optional<ModuleWeaponCapability>  weaponCapability;
     std::optional<ModuleSalvageCapability> salvageCapability;
     std::optional<ModuleRepairCapability>  repairCapability;
+
+    // Optional hover-tooltip text for the module selection button
+    // (REQ-MOD-UI-MODULE-TOOLTIP).
+    std::optional<std::string> tooltip;
 };
 
 struct ModulesConfig

src/lib/config/RecipesConfig.h

@@ -36,6 +36,10 @@ struct RecipeDef
     // at game start. >= 0 = locked; schematic enters drop pool at that station
     // level once the output item is implicitly unlocked (REQ-LOCK-EXPLICIT).
     std::optional<int> unlockAtStationLevel;
+    // Assembler recipe schematics only. Prerequisite schematic ids that must be
+    // explicitly unlocked before this schematic can enter the drop pool
+    // (REQ-LOCK-PREREQ). Empty = none.
+    std::vector<std::string> unlockRequires;
 };
 
 struct RecipesConfig

src/lib/config/ShipsConfig.h

@@ -36,6 +36,9 @@ struct ShipDef
 {
     std::string id;
     int unlockAtStationLevel;
+    // Prerequisite schematic ids that must be explicitly unlocked before this
+    // schematic can enter the drop pool (REQ-LOCK-PREREQ). Empty = none.
+    std::vector<std::string> unlockRequires;
     std::vector<std::string> layout;
 
     ShipSchematic schematic;

src/lib/config/WorldConfig.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <optional>
+#include <string>
+
 #include "Formula.h"
 
 // Region widths are in tiles (REQ-GW-REGIONS).
@@ -14,8 +17,8 @@ struct WorldRegions
 // Asteroid expansion (REQ-EXP-UNLOCK, REQ-EXP-COST).
 struct WorldExpansion
 {
-    int columnsPerExpansion_tiles;
-    int costBuildingBlocks;
+    int     columnsPerExpansion_tiles;
+    Formula costBuildingBlocksFormula;  // cost in building blocks; x = expansions already purchased
 };
 
 // Push effects (REQ-PSH-*, REQ-WAV-BOSS-ADVANCE).
@@ -53,6 +56,14 @@ struct WorldArtifacts
     int     artifactWinCount;
 };
 
+// View pan speed (REQ-UI-SCROLL-SPEED). Presentation-only; the simulation ignores these.
+struct WorldScroll
+{
+    double panSpeedSlow_tps;        // tiles/s, used outside the contest zone
+    double panSpeedFast_tps;        // tiles/s, used inside the contest zone
+    int    panRampBandWidth_tiles;  // full width of the ramp band straddling each contest-zone boundary
+};
+
 struct WorldConfig
 {
     int heightTiles;                    // REQ-GW-HEIGHT
@@ -67,10 +78,15 @@ struct WorldConfig
     double orbitFactor;                 // REQ-SHP-ORBIT (multiplies tool range for orbit radius)
     double rallyOrbitRadius_tiles;      // REQ-SHP-ORBIT (fixed orbit radius around the rally point)
 
+    // Optional hover-tooltip for the header building blocks stock display
+    // (REQ-UI-BLOCKS-TOOLTIP). Presentation-only; the simulation ignores it.
+    std::optional<std::string> buildingBlocksTooltip;
+
     WorldRegions regions;
     WorldExpansion expansion;
     WorldPush push;
     WorldWaves waves;
     WorldTargeting targeting;
     WorldArtifacts artifacts;
+    WorldScroll scroll;
 };

src/lib/core/SchematicChoiceOption.h

@@ -20,8 +20,8 @@ struct SchematicChoiceOption
     SchematicType type;
     std::string displayName;
 
-    // Display names of items produced by recipes that would newly become
-    // implicitly unlocked (REQ-LOCK-IMPLICIT) if this option is selected.
-    // Deduplicated and sorted alphabetically; empty if none.
-    std::vector<std::string> newlyUnlockedItemNames;
+    // Ids of miner/assembler recipes that would newly become implicitly
+    // unlocked (REQ-LOCK-IMPLICIT) if this option is selected. Sorted
+    // alphabetically by display name; empty if none.
+    std::vector<std::string> newlyUnlockedRecipeIds;
 };

src/lib/ecs/system/ScrapSystem.cpp

@@ -69,9 +69,9 @@ std::vector<ScrapInfo> ScrapSystem::allScrapInfo() const
 {
     std::vector<ScrapInfo> result;
     m_admin.forEach<ScrapDataComponent>(
-        [&result, this](entt::entity e, const ScrapDataComponent& /*sd*/)
+        [&result, this](entt::entity e, const ScrapDataComponent& sd)
         {
-            result.push_back(ScrapInfo{e, m_admin.get<PositionComponent>(e).value});
+            result.push_back(ScrapInfo{e, m_admin.get<PositionComponent>(e).value, sd.amount});
         });
     return result;
 }

src/lib/ecs/system/ScrapSystem.h

@@ -15,6 +15,7 @@ struct ScrapInfo
 {
     entt::entity entity;
     QVector2D position;
+    int amount;
 };
 
 class ScrapSystem

src/lib/eventsystem/event/CMakeLists.txt

@@ -3,6 +3,7 @@ SET(HDRS
 	${CMAKE_CURRENT_SOURCE_DIR}/TracePrintRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/TickAdvancedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/BuildingBlocksChangedEvent.h
+	${CMAKE_CURRENT_SOURCE_DIR}/ExpansionCostChangedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/EntitySelectedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/GameSpeedChangedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/BossWaveUpdatedEvent.h
@@ -21,6 +22,7 @@ SET(HDRS
 	${CMAKE_CURRENT_SOURCE_DIR}/DemolishModeToggleRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/BlueprintPlacementRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/ExitBlueprintModeRequestedEvent.h
+	${CMAKE_CURRENT_SOURCE_DIR}/TemporaryBlueprintRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/SpeedChangeRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/LayoutDialogRequestedEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/RecipeSelectionRequestedEvent.h
@@ -30,6 +32,7 @@ SET(HDRS
 	${CMAKE_CURRENT_SOURCE_DIR}/BeamFiredEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/DebugDrawToggledEvent.h
 	${CMAKE_CURRENT_SOURCE_DIR}/CommandRequestedEvent.h
+	${CMAKE_CURRENT_SOURCE_DIR}/PlayerCommandsAppliedEvent.h
 	PARENT_SCOPE
 )
 

src/lib/eventsystem/event/ExpansionCostChangedEvent.h

@@ -0,0 +1,17 @@
+#ifndef EXPANSION_COST_CHANGED_EVENT_H
+#define EXPANSION_COST_CHANGED_EVENT_H
+
+#include "Event.h"
+
+// Fired when the current asteroid-expansion cost changes (REQ-EXP-COST): once at
+// startup and again after each expansion is purchased. Carries the cost in
+// building blocks so the header Expand button can update its caption/enabled
+// state (REQ-UI-EXPAND-BUTTON).
+class ExpansionCostChangedEvent : public Event
+{
+public:
+	explicit ExpansionCostChangedEvent(int cost) : cost(cost) {}
+	const int cost;
+};
+
+#endif   // EXPANSION_COST_CHANGED_EVENT_H

src/lib/eventsystem/event/PlayerCommandsAppliedEvent.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "Event.h"
+
+// Emitted by GameWorldView once per frame after queued player commands have been
+// drained and applied to the simulation. It lets presentation widgets refresh
+// even while the game is paused (no tick advances, so no TickAdvancedEvent), for
+// example so a shipyard's layout preview appears immediately after its schematic
+// is chosen. It is a UI notification only and never feeds back into the command
+// queue, so it has no effect on replay recording or determinism.
+class PlayerCommandsAppliedEvent : public Event
+{
+};

src/lib/eventsystem/event/ScrapSelectionChangedEvent.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <vector>
+
+#include "entt/entity/entity.hpp"
+
+#include "Event.h"
+
+// The set of currently selected scrap piles (REQ-UI-SCRAP-CLICK-SELECT,
+// REQ-UI-SCRAP-MULTI-SELECT). An empty list means no scrap is selected. Scrap forms
+// its own selection category, mutually exclusive with buildings and entities.
+class ScrapSelectionChangedEvent : public Event
+{
+public:
+    explicit ScrapSelectionChangedEvent(std::vector<entt::entity> scrap)
+        : scrap(std::move(scrap)) {}
+    const std::vector<entt::entity> scrap;
+};

src/lib/eventsystem/event/TemporaryBlueprintRequestedEvent.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "Event.h"
+
+// Emitted when the player presses the temporary-blueprint hotkey (REQ-UI-BLUEPRINT-TEMP).
+// Carries no payload: the blueprint is built from the current selection by the receiver.
+class TemporaryBlueprintRequestedEvent : public Event
+{
+};

src/lib/sim/BeltSlot.cpp

@@ -0,0 +1,45 @@
+#include "BeltSlot.h"
+
+#include <cstddef>
+
+void advanceBeltSlots(std::vector<BeltItemSlot>& slots, double progressPerTick)
+{
+    for (std::size_t i = 0; i < slots.size(); ++i)
+    {
+        slots[i].progress += progressPerTick;
+
+        // Absolute cap: slot i cannot exceed 1.0 - i * 0.25.
+        const double absoluteCap = 1.0 - static_cast<double>(i) * 0.25;
+        if (slots[i].progress > absoluteCap)
+        {
+            slots[i].progress = absoluteCap;
+        }
+
+        // Gap constraint: must stay 0.25 behind the slot ahead.
+        if (i > 0)
+        {
+            const double gapCap = slots[i - 1].progress - 0.25;
+            if (slots[i].progress > gapCap)
+            {
+                slots[i].progress = (gapCap < 0.0 ? 0.0 : gapCap);
+            }
+        }
+    }
+}
+
+QPointF beltSlotWorldPos(QPoint tile, Rotation dir, double progress)
+{
+    // Map progress [0, 1] along the belt direction to a fractional tile-unit position.
+    // Progress 0 = entered from opposite side; 1 = at output edge.
+    const double baseX = tile.x() + 0.5;
+    const double baseY = tile.y() + 0.5;
+
+    switch (dir)
+    {
+        case Rotation::North: return {baseX, baseY - (progress - 0.5)};
+        case Rotation::East:  return {baseX + (progress - 0.5), baseY};
+        case Rotation::South: return {baseX, baseY + (progress - 0.5)};
+        case Rotation::West:  return {baseX - (progress - 0.5), baseY};
+    }
+    return {baseX, baseY};
+}

src/lib/sim/BeltSlot.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <vector>
+
+#include <QPoint>
+#include <QPointF>
+
+#include "Item.h"
+#include "Rotation.h"
+
+// A single item on a belt-like lane: an item plus its fractional progress along
+// the lane's travel direction. Shared by BeltSystem's belt/tunnel tiles and by a
+// building's virtual output belt (REQ-MAT-OUTPUT-EMERGE) so the packing and
+// geometry live in exactly one place.
+struct BeltItemSlot
+{
+    Item   item;
+    double progress;  // [0.0, 1.0]: 0 = just entered, 1 = at output edge
+};
+
+// Advances every slot in `slots` by `progressPerTick`, applying the standard belt
+// packing: the front (index 0) carries the highest progress; each following slot
+// stays at least 0.25 behind the slot ahead and is capped at 1.0 - i * 0.25.
+// `slots` must be ordered front (highest progress) first. This is the per-tile
+// advance shared by belts, tunnel entries, and tunnel exits.
+void advanceBeltSlots(std::vector<BeltItemSlot>& slots, double progressPerTick);
+
+// World-space centre (in tile units) of a slot at `progress` on a lane occupying
+// `tile` and flowing in `dir`. Progress 0 = entry edge, 1 = output edge.
+QPointF beltSlotWorldPos(QPoint tile, Rotation dir, double progress);

src/lib/sim/BeltSystem.cpp

@@ -27,21 +27,54 @@ QPoint BeltSystem::adjacentTile(QPoint tile, Rotation dir)
     return tile;
 }
 
-QPointF BeltSystem::slotWorldPos(QPoint tile, Rotation dir, double progress)
+Rotation BeltSystem::oppositeRotation(Rotation dir)
 {
-    // Map progress [0, 1] along the belt direction to a fractional tile-unit position.
-    // Progress 0 = entered from opposite side; 1 = at output edge.
-    double baseX = tile.x() + 0.5;
-    double baseY = tile.y() + 0.5;
-
     switch (dir)
     {
-        case Rotation::North: return {baseX, baseY - (progress - 0.5)};
-        case Rotation::East:  return {baseX + (progress - 0.5), baseY};
-        case Rotation::South: return {baseX, baseY + (progress - 0.5)};
-        case Rotation::West:  return {baseX - (progress - 0.5), baseY};
+        case Rotation::North: return Rotation::South;
+        case Rotation::East:  return Rotation::West;
+        case Rotation::South: return Rotation::North;
+        case Rotation::West:  return Rotation::East;
     }
-    return {baseX, baseY};
+    return dir;
+}
+
+bool BeltSystem::entersThroughOutputEdge(QPoint tile, Rotation travelDir) const
+{
+    // An item travelling in travelDir crosses into the tile through the edge
+    // opposite that direction.  If that entry edge is one of the tile's output
+    // edges, the tile must refuse the item (REQ-MAT-ACCEPT-DIR).
+    const Rotation entryEdge = oppositeRotation(travelDir);
+
+    const std::map<std::pair<int, int>, BeltTile>::const_iterator beltIt =
+        m_belts.find(key(tile));
+    if (beltIt != m_belts.end())
+    {
+        return entryEdge == beltIt->second.direction;
+    }
+
+    const std::map<std::pair<int, int>, SplitterTile>::const_iterator splIt =
+        m_splitters.find(key(tile));
+    if (splIt != m_splitters.end())
+    {
+        return entryEdge == splIt->second.outputA || entryEdge == splIt->second.outputB;
+    }
+
+    const std::map<std::pair<int, int>, TunnelEntryTile>::const_iterator teIt =
+        m_tunnelEntries.find(key(tile));
+    if (teIt != m_tunnelEntries.end())
+    {
+        return entryEdge == teIt->second.direction;
+    }
+
+    const std::map<std::pair<int, int>, TunnelExitTile>::const_iterator txIt =
+        m_tunnelExits.find(key(tile));
+    if (txIt != m_tunnelExits.end())
+    {
+        return entryEdge == txIt->second.direction;
+    }
+
+    return false;
 }
 
 // ---------------------------------------------------------------------------
@@ -202,6 +235,12 @@ void BeltSystem::reevaluateTunnelPairing()
 
 bool BeltSystem::tryPutItem(QPoint tile, Item item, Rotation fromDir)
 {
+    // Refuse items that would enter through the tile's output edge (REQ-MAT-ACCEPT-DIR).
+    if (entersThroughOutputEdge(tile, fromDir))
+    {
+        return false;
+    }
+
     const std::map<std::pair<int, int>, BeltTile>::iterator bIt = m_belts.find(key(tile));
     if (bIt != m_belts.end())
     {
@@ -411,29 +450,7 @@ void BeltSystem::advanceProgress()
     for (std::map<std::pair<int, int>, BeltTile>::iterator it = m_belts.begin();
          it != m_belts.end(); ++it)
     {
-        BeltTile& bt = it->second;
-
-        for (std::size_t i = 0; i < bt.itemSlots.size(); ++i)
-        {
-            bt.itemSlots[i].progress += m_progressPerTick_tpt;
-
-            // Absolute cap: slot i cannot exceed 1.0 - i * 0.25.
-            const double absoluteCap = 1.0 - i * 0.25;
-            if (bt.itemSlots[i].progress > absoluteCap)
-            {
-                bt.itemSlots[i].progress = absoluteCap;
-            }
-
-            // Gap constraint: must stay 0.25 behind the slot ahead.
-            if (i > 0)
-            {
-                const double gapCap = bt.itemSlots[i - 1].progress - 0.25;
-                if (bt.itemSlots[i].progress > gapCap)
-                {
-                    bt.itemSlots[i].progress = (gapCap < 0.0 ? 0.0 : gapCap);
-                }
-            }
-        }
+        advanceBeltSlots(it->second.itemSlots, m_progressPerTick_tpt);
     }
 
     for (std::map<std::pair<int, int>, SplitterTile>::iterator it = m_splitters.begin();
@@ -489,53 +506,13 @@ void BeltSystem::advanceTunnelProgress()
     for (std::map<std::pair<int, int>, TunnelEntryTile>::iterator it = m_tunnelEntries.begin();
          it != m_tunnelEntries.end(); ++it)
     {
-        TunnelEntryTile& te = it->second;
-
-        for (std::size_t i = 0; i < te.itemSlots.size(); ++i)
-        {
-            te.itemSlots[i].progress += m_progressPerTick_tpt;
-
-            const double absoluteCap = 1.0 - i * 0.25;
-            if (te.itemSlots[i].progress > absoluteCap)
-            {
-                te.itemSlots[i].progress = absoluteCap;
-            }
-
-            if (i > 0)
-            {
-                const double gapCap = te.itemSlots[i - 1].progress - 0.25;
-                if (te.itemSlots[i].progress > gapCap)
-                {
-                    te.itemSlots[i].progress = (gapCap < 0.0 ? 0.0 : gapCap);
-                }
-            }
-        }
+        advanceBeltSlots(it->second.itemSlots, m_progressPerTick_tpt);
     }
 
     for (std::map<std::pair<int, int>, TunnelExitTile>::iterator it = m_tunnelExits.begin();
          it != m_tunnelExits.end(); ++it)
     {
-        TunnelExitTile& tx = it->second;
-
-        for (std::size_t i = 0; i < tx.itemSlots.size(); ++i)
-        {
-            tx.itemSlots[i].progress += m_progressPerTick_tpt;
-
-            const double absoluteCap = 1.0 - i * 0.25;
-            if (tx.itemSlots[i].progress > absoluteCap)
-            {
-                tx.itemSlots[i].progress = absoluteCap;
-            }
-
-            if (i > 0)
-            {
-                const double gapCap = tx.itemSlots[i - 1].progress - 0.25;
-                if (tx.itemSlots[i].progress > gapCap)
-                {
-                    tx.itemSlots[i].progress = (gapCap < 0.0 ? 0.0 : gapCap);
-                }
-            }
-        }
+        advanceBeltSlots(it->second.itemSlots, m_progressPerTick_tpt);
     }
 
     for (TunnelLink& link : m_tunnelLinks)
@@ -579,6 +556,13 @@ void BeltSystem::moveItemsToNextTile()
         const QPoint here  = QPoint(it->first.first, it->first.second);
         const QPoint next  = adjacentTile(here, bt.direction);
 
+        // Refuse to hand off into a downstream tile's output edge (REQ-MAT-ACCEPT-DIR);
+        // the item stays blocked at progress 1.0.
+        if (entersThroughOutputEdge(next, bt.direction))
+        {
+            continue;
+        }
+
         const std::map<std::pair<int, int>, BeltTile>::iterator nextBelt = m_belts.find(key(next));
         const std::map<std::pair<int, int>, SplitterTile>::iterator nextSplitter = m_splitters.find(key(next));
 
@@ -804,6 +788,12 @@ bool BeltSystem::tryPlaceOnBelt(QPoint tile, Item item)
 
 bool BeltSystem::tryPushToTile(QPoint dest, Item item, Rotation fromDir)
 {
+    // Refuse items that would enter through the tile's output edge (REQ-MAT-ACCEPT-DIR).
+    if (entersThroughOutputEdge(dest, fromDir))
+    {
+        return false;
+    }
+
     if (tryPlaceOnBelt(dest, item))
     {
         return true;
@@ -871,7 +861,7 @@ void BeltSystem::forEachVisualItem(QRect viewportTiles,
         {
             VisualItem vi;
             vi.type     = bt.itemSlots[i].item.type;
-            vi.worldPos = slotWorldPos(tile, bt.direction, bt.itemSlots[i].progress);
+            vi.worldPos = beltSlotWorldPos(tile, bt.direction, bt.itemSlots[i].progress);
             visit(vi);
         }
     }
@@ -891,7 +881,7 @@ void BeltSystem::forEachVisualItem(QRect viewportTiles,
         {
             VisualItem vi;
             vi.type     = st.back[i].item.type;
-            vi.worldPos = slotWorldPos(tile, st.backDir[i], st.back[i].progress);
+            vi.worldPos = beltSlotWorldPos(tile, st.backDir[i], st.back[i].progress);
             visit(vi);
         }
 
@@ -917,7 +907,7 @@ void BeltSystem::forEachVisualItem(QRect viewportTiles,
             {
                 VisualItem vi;
                 vi.type     = slot->item.type;
-                vi.worldPos = slotWorldPos(tile, dir, slot->progress);
+                vi.worldPos = beltSlotWorldPos(tile, dir, slot->progress);
                 visit(vi);
             }
         };
@@ -947,7 +937,7 @@ void BeltSystem::forEachVisualItem(QRect viewportTiles,
         {
             VisualItem vi;
             vi.type     = te.itemSlots[i].item.type;
-            vi.worldPos = slotWorldPos(tile, te.direction, te.itemSlots[i].progress);
+            vi.worldPos = beltSlotWorldPos(tile, te.direction, te.itemSlots[i].progress);
             visit(vi);
         }
     }
@@ -965,7 +955,7 @@ void BeltSystem::forEachVisualItem(QRect viewportTiles,
         {
             VisualItem vi;
             vi.type     = tx.itemSlots[i].item.type;
-            vi.worldPos = slotWorldPos(tile, tx.direction, tx.itemSlots[i].progress);
+            vi.worldPos = beltSlotWorldPos(tile, tx.direction, tx.itemSlots[i].progress);
             visit(vi);
         }
     }

src/lib/sim/BeltSystem.h

@@ -10,6 +10,7 @@
 #include <QPointF>
 #include <QRect>
 
+#include "BeltSlot.h"
 #include "Item.h"
 #include "ItemType.h"
 #include "Port.h"
@@ -74,8 +75,10 @@ public:
     // port.direction = direction items flow on that tile
     //
     // tryPutItem: place item onto tile.
-    //   Returns false if the tile is not a belt/splitter, or tile full.
-    //   fromDir: travel direction of the item (used for splitter animation).
+    //   Returns false if the tile is not a belt/splitter/tunnel entry, tile full,
+    //   or the item would enter through the tile's output edge (REQ-MAT-ACCEPT-DIR).
+    //   fromDir: travel direction of the item (used for splitter animation and for
+    //   the output-edge check).
     bool tryPutItem(QPoint tile, Item item, Rotation fromDir = Rotation::West);
 
     // tryTakeItem: remove and return the leading item from port.tile.
@@ -86,6 +89,11 @@ public:
     //   Returns nullopt if tile is not a belt, direction mismatches, or tile empty.
     std::optional<ItemType> peekItem(Port port) const;
 
+    // Progress advanced per tick at the configured belt speed (tile fraction per
+    // tick). Shared with building output belts so emerging items travel at exactly
+    // the same speed as real belts (REQ-MAT-OUTPUT-EMERGE).
+    double getProgressPerTick_tpt() const { return m_progressPerTick_tpt; }
+
     // -- Maintenance ---------------------------------------------------------
     void clearTiles(const std::vector<QPoint>& tiles);   // REQ-UI-BELT-CLEAR
     void tick();
@@ -117,15 +125,12 @@ private:
 
     static std::pair<int, int> key(QPoint tile);
     static QPoint adjacentTile(QPoint tile, Rotation dir);
+    static Rotation oppositeRotation(Rotation dir);
 
-    // Returns the world-space centre of a slot given tile origin and progress.
-    static QPointF slotWorldPos(QPoint tile, Rotation dir, double progress);
-
-    struct BeltItemSlot
-    {
-        Item item;
-        double progress;  // [0.0, 1.0]: 0 = just entered, 1 = at output edge
-    };
+    // True if an item travelling in travelDir would enter the transport tile at
+    // `tile` through one of that tile's output edges (and must therefore be
+    // refused).  Returns false if no transport tile occupies `tile`.
+    bool entersThroughOutputEdge(QPoint tile, Rotation travelDir) const;
 
     struct BeltTile
     {

src/lib/sim/Building.h

@@ -12,6 +12,7 @@
 #include "BuildingId.h"
 
 #include "entt/entity/entity.hpp"
+#include "BeltSlot.h"
 #include "Item.h"
 #include "ItemType.h"
 #include "Port.h"
@@ -75,6 +76,51 @@ struct Building
     OutputBuffer outputBuffer;
     std::optional<Production> production;
 
+    // Items currently emerging from each output port on its virtual output belt
+    // (REQ-MAT-OUTPUT-EMERGE); one lane per output port, parallel to outputPorts.
+    // Each lane holds slots at progress [0.5, 1.0], front (highest progress) first.
+    // An emerging item still counts as residing in the output buffer until it hands
+    // off onto a real belt at progress 1.0.
+    std::vector<std::vector<BeltItemSlot>> emergingItems;
+
+    // Total items held on the output side: buffered plus still-emerging. The
+    // output-buffer capacity rule (REQ-MAT-OUTPUT-BUFFER) counts emerging items,
+    // since they have not yet left the building.
+    int outputItemCount() const
+    {
+        int count = static_cast<int>(outputBuffer.items.size());
+        for (const std::vector<BeltItemSlot>& lane : emergingItems)
+        {
+            count += static_cast<int>(lane.size());
+        }
+        return count;
+    }
+
+    // Items currently travelling inward on each input port's virtual input belt
+    // (REQ-MAT-INPUT-INTAKE); one lane per input port, parallel to inputPorts. Each
+    // lane holds slots at progress [0.0, 0.5], front (highest progress) first. An
+    // in-transit item has reserved a slot in its per-material input buffer but is
+    // not yet consumable — it enters the buffer only on reaching progress 0.5.
+    std::vector<std::vector<BeltItemSlot>> incomingItems;
+
+    // Buffered plus in-transit count of one input material. The acceptance/space
+    // test (REQ-MAT-INPUT-PORTS, REQ-MAT-INPUT-INTAKE) counts in-transit items, so
+    // buffered + reserved never exceeds the material's cap (REQ-MAT-INPUT-BUFFER).
+    int pendingInputCount(const ItemType& type) const
+    {
+        int count = 0;
+        const std::map<ItemType, int>::const_iterator it = inputBuffer.counts.find(type);
+        if (it != inputBuffer.counts.end()) { count = it->second; }
+        for (const std::vector<BeltItemSlot>& lane : incomingItems)
+        {
+            for (const BeltItemSlot& slot : lane)
+            {
+                if (slot.item.type == type) { ++count; }
+            }
+        }
+        return count;
+    }
+
     // Pre-computed from surface mask at placement; in absolute world coordinates.
     std::vector<QPoint> bodyCells;
     std::vector<Port>   outputPorts;

src/lib/sim/BuildingConfig.cpp

@@ -0,0 +1,167 @@
+#include "BuildingConfig.h"
+
+#include <algorithm>
+#include <climits>
+
+#include "BeltSystem.h"
+#include "Building.h"
+#include "BuildingSystem.h"
+#include "Simulation.h"
+
+namespace
+{
+// The blueprint-relevant geometry shared by operational buildings and construction
+// sites. Resolved from whichever of the two a selected id refers to.
+struct SelectedBuilding
+{
+    BuildingId                id;
+    BuildingType              type;
+    Rotation                  rotation;
+    QPoint                    anchor;
+    const std::vector<QPoint>* bodyCells;
+};
+
+// Resolves a selected id to a player-placeable building or construction site, if it
+// is one. Returns std::nullopt for an unknown id or a non-player-placeable building
+// (the HQ and defence stations, per REQ-UI-BLUEPRINT-CREATE).
+std::optional<SelectedBuilding> resolvePlaceable(const Simulation& sim, BuildingId id)
+{
+    const Building*         building = sim.buildings().findBuilding(id);
+    const ConstructionSite* site     = building ? nullptr : sim.buildings().findSite(id);
+    if (!building && !site)
+    {
+        return std::nullopt;
+    }
+
+    const BuildingType  type = building ? building->type : site->type;
+    const BuildingDef*  def  = sim.config().buildings.findBuildingDef(type);
+    if (!def || !def->playerPlaceable)
+    {
+        return std::nullopt;
+    }
+
+    SelectedBuilding resolved;
+    resolved.id        = id;
+    resolved.type      = type;
+    resolved.rotation  = building ? building->rotation : site->rotation;
+    resolved.anchor    = building ? building->anchor : site->anchor;
+    resolved.bodyCells = building ? &building->bodyCells : &site->bodyCells;
+    return resolved;
+}
+} // namespace
+
+std::optional<BuildingConfig> readBuildingConfig(const Simulation& sim, BuildingId id)
+{
+    const Building*         building = sim.buildings().findBuilding(id);
+    const ConstructionSite* site     = building ? nullptr : sim.buildings().findSite(id);
+    if (!building && !site)
+    {
+        return std::nullopt;
+    }
+
+    BuildingConfig config;
+    config.type = building ? building->type : site->type;
+
+    const std::string& recipeId = building ? building->recipeId : site->recipeId;
+    if (!recipeId.empty())
+    {
+        config.recipeId = recipeId;
+    }
+
+    config.shipLayout = building ? building->shipLayout : site->shipLayout;
+
+    if (config.type == BuildingType::Splitter)
+    {
+        config.isSplitter = true;
+        if (building)
+        {
+            // Operational splitter filters live in the BeltSystem, keyed by tile.
+            const std::optional<BeltSystem::SplitterInfo> info =
+                sim.belts().getSplitterInfo(building->anchor);
+            if (info.has_value())
+            {
+                config.splitterFilterA = info->filterA;
+                config.splitterFilterB = info->filterB;
+            }
+        }
+        else
+        {
+            // A site keeps its pre-completion filters on the ConstructionSite.
+            config.splitterFilterA = site->splitterFilterA;
+            config.splitterFilterB = site->splitterFilterB;
+        }
+    }
+
+    return config;
+}
+
+Blueprint captureBlueprintFromSelection(const Simulation&              sim,
+                                        const std::vector<BuildingId>& selectedIds)
+{
+    std::vector<SelectedBuilding> entries;
+    entries.reserve(selectedIds.size());
+    for (const BuildingId id : selectedIds)
+    {
+        const std::optional<SelectedBuilding> resolved = resolvePlaceable(sim, id);
+        if (resolved.has_value())
+        {
+            entries.push_back(*resolved);
+        }
+    }
+
+    if (entries.empty())
+    {
+        return Blueprint{};
+    }
+
+    int minX = INT_MAX, maxX = INT_MIN;
+    int minY = INT_MAX, maxY = INT_MIN;
+    for (const SelectedBuilding& e : entries)
+    {
+        for (const QPoint& cell : *e.bodyCells)
+        {
+            minX = std::min(minX, cell.x());
+            maxX = std::max(maxX, cell.x());
+            minY = std::min(minY, cell.y());
+            maxY = std::max(maxY, cell.y());
+        }
+    }
+
+    const QPoint center((minX + maxX) / 2, (minY + maxY) / 2);
+
+    Blueprint blueprint;
+    blueprint.buildings.reserve(entries.size());
+    for (const SelectedBuilding& e : entries)
+    {
+        BlueprintBuilding building;
+        building.type     = e.type;
+        building.rotation = e.rotation;
+        building.offset   = e.anchor - center;
+        // Recipe / schematic / layout / splitter-filter capture is shared with the
+        // copy-settings gesture (REQ-BLD-COPY-CONFIG) via readBuildingConfig, which
+        // handles operational buildings and construction sites alike.
+        const std::optional<BuildingConfig> config = readBuildingConfig(sim, e.id);
+        if (config.has_value())
+        {
+            building.recipeId        = config->recipeId.value_or(std::string());
+            building.shipLayout      = config->shipLayout;
+            building.splitterFilterA = config->splitterFilterA;
+            building.splitterFilterB = config->splitterFilterB;
+        }
+        blueprint.buildings.push_back(building);
+    }
+    return blueprint;
+}
+
+bool selectionHasPlaceableBuilding(const Simulation&              sim,
+                                   const std::vector<BuildingId>& selectedIds)
+{
+    for (const BuildingId id : selectedIds)
+    {
+        if (resolvePlaceable(sim, id).has_value())
+        {
+            return true;
+        }
+    }
+    return false;
+}

src/lib/sim/BuildingConfig.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "Blueprint.h"
+#include "BuildingId.h"
+#include "BuildingType.h"
+#include "ItemType.h"
+#include "ShipLayout.h"
+
+class Simulation;
+
+// The user-configurable settings of a single building or construction site: the
+// selected recipe / ship schematic, the shipyard module layout, and (for
+// splitters) the two output filters. Shared by the copy-settings gesture
+// (REQ-BLD-COPY-CONFIG) and blueprint capture (REQ-UI-BLUEPRINT-STORAGE).
+struct BuildingConfig
+{
+    BuildingType type = BuildingType::Miner;
+
+    // Selected recipe (Miner / Assembler) or ship schematic id (Shipyard); unset
+    // when nothing is selected.
+    std::optional<std::string> recipeId;
+
+    // Shipyard module layout (REQ-MOD-LAYOUT).
+    std::optional<ShipLayoutConfig> shipLayout;
+
+    // Splitter output filters (empty = accept all). isSplitter distinguishes an
+    // empty-filter splitter (a valid accept-all configuration) from a building
+    // type that has no splitter filters at all.
+    bool                  isSplitter = false;
+    std::vector<ItemType> splitterFilterA;
+    std::vector<ItemType> splitterFilterB;
+};
+
+// Reads the current configuration of the building or construction site identified
+// by id, handling operational buildings and sites alike. Returns std::nullopt if
+// no such building or site exists.
+std::optional<BuildingConfig> readBuildingConfig(const Simulation& sim, BuildingId id);
+
+// Captures a blueprint from a selection of building / construction-site ids, keeping
+// only player-placeable buildings and recording each one's type, rotation, offset
+// from the selection's bounding-box center, and configuration. Operational buildings
+// and construction sites are treated identically (REQ-UI-BLUEPRINT-CREATE,
+// REQ-UI-BLUEPRINT-STORAGE). The returned blueprint is unnamed.
+Blueprint captureBlueprintFromSelection(const Simulation&              sim,
+                                        const std::vector<BuildingId>& selectedIds);
+
+// True if any selected id refers to a player-placeable building or construction site
+// (the enable condition for the Create Blueprint button, REQ-UI-BLUEPRINT-CREATE).
+bool selectionHasPlaceableBuilding(const Simulation&              sim,
+                                   const std::vector<BuildingId>& selectedIds);

src/lib/sim/BuildingSystem.cpp

@@ -1,5 +1,6 @@
 #include "BuildingSystem.h"
 
+#include <algorithm>
 #include <cassert>
 #include <limits>
 #include <random>
@@ -9,6 +10,57 @@
 #include "SurfaceMask.h"
 #include "tracing.h"
 
+namespace
+{
+// Smelter and Reprocessing Plant have no player-selected recipe
+// (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING). They auto-process whatever inputs
+// they receive, matching against every recipe of their building type.
+bool isAutoRecipeBuildingType(BuildingType type)
+{
+    return type == BuildingType::Smelter
+        || type == BuildingType::ReprocessingPlant;
+}
+
+// The building body tile that owns an output port, given the port's outside tile
+// (port.tile) and its facing direction. The virtual output belt occupies this tile
+// and flows toward port.tile (REQ-MAT-OUTPUT-EMERGE).
+QPoint outputBodyTile(QPoint portTile, Rotation direction)
+{
+    switch (direction)
+    {
+        case Rotation::East:  return portTile + QPoint(-1,  0);
+        case Rotation::West:  return portTile + QPoint( 1,  0);
+        case Rotation::North: return portTile + QPoint( 0,  1);
+        case Rotation::South: return portTile + QPoint( 0, -1);
+    }
+    return portTile;
+}
+
+// The building body tile an input port feeds into, given the port's outside belt
+// tile (port.tile) and its inward flow direction. The virtual input belt occupies
+// this tile and flows from the outer edge (progress 0.0) to the centre (0.5)
+// (REQ-MAT-INPUT-INTAKE).
+QPoint inputBodyTile(QPoint portTile, Rotation inwardDirection)
+{
+    switch (inwardDirection)
+    {
+        case Rotation::East:  return portTile + QPoint( 1,  0);
+        case Rotation::West:  return portTile + QPoint(-1,  0);
+        case Rotation::North: return portTile + QPoint( 0, -1);
+        case Rotation::South: return portTile + QPoint( 0,  1);
+    }
+    return portTile;
+}
+
+// An input belt accepts a new item at progress 0.0 only when it holds fewer than
+// three items and the entry slot is clear (nothing within a quarter tile of 0.0),
+// matching the belt packing used elsewhere (REQ-GW-BELT-CAPACITY).
+bool inputLaneEntryFree(const std::vector<BeltItemSlot>& lane)
+{
+    return lane.size() < 3 && (lane.empty() || lane.back().progress >= 0.25);
+}
+}  // namespace
+
 BuildingSystem::BuildingSystem(const GameConfig& config,
                                BeltSystem& belts,
                                std::function<BuildingId()> allocateBuildingId,
@@ -24,6 +76,7 @@ BuildingSystem::BuildingSystem(const GameConfig& config,
     , m_spawnShip(std::move(spawnShip))
     , m_isItemUnlocked(std::move(isItemUnlocked))
     , m_rng(rng)
+    , m_asteroidWidth_tiles(config.world.regions.asteroidWidth_tiles)
 {
 }
 
@@ -117,6 +170,56 @@ void BuildingSystem::initBuffers(Building& b, const RecipeDef& recipe) const
     }
 }
 
+void BuildingSystem::initAutoBuffers(Building& b) const
+{
+    b.inputBuffer.counts.clear();
+    b.inputBuffer.caps.clear();
+
+    // Union the inputs of every recipe of this building type; the cap for each
+    // item is twice the largest per-cycle requirement across those recipes.
+    // Output capacity follows the same rules as initBuffers: the Reprocessing
+    // Plant holds one cycle's max output (REQ-MAT-OUTPUT-BUFFER-REPROCESSING),
+    // other auto buildings hold twice the largest per-cycle output.
+    int outputCapacity = 0;
+    for (const RecipeDef& recipe : m_config.recipes.recipes)
+    {
+        if (recipe.building != b.type)
+        {
+            continue;
+        }
+
+        for (const RecipeIngredient& ing : recipe.inputs)
+        {
+            const ItemType type{ing.item};
+            b.inputBuffer.counts[type] = 0;
+            b.inputBuffer.caps[type] =
+                std::max(b.inputBuffer.caps[type], 2 * ing.amount);
+        }
+
+        if (b.type == BuildingType::ReprocessingPlant)
+        {
+            int maxAmount = 0;
+            for (const RecipeOutput& out : recipe.outputs)
+            {
+                maxAmount = std::max(maxAmount, out.amount);
+            }
+            outputCapacity = std::max(outputCapacity, maxAmount);
+        }
+        else
+        {
+            int totalAmount = 0;
+            for (const RecipeOutput& out : recipe.outputs)
+            {
+                totalAmount += out.amount;
+            }
+            outputCapacity = std::max(outputCapacity, 2 * totalAmount);
+        }
+    }
+
+    b.outputBuffer.items.clear();
+    b.outputBuffer.capacity = outputCapacity;
+}
+
 void BuildingSystem::initShipyardBuffers(Building& b) const
 {
     b.inputBuffer.counts.clear();
@@ -153,6 +256,16 @@ void BuildingSystem::initShipyardBuffers(Building& b) const
     }
 }
 
+void BuildingSystem::initSalvageBayBuffer(Building& b) const
+{
+    // Salvage Bay has no recipe-driven buffer; its output-buffer holding size for
+    // ship drop-off is config-defined (REQ-BLD-SALVAGE-BAY).
+    b.outputBuffer.items.clear();
+    const BuildingDef* def = findBuildingDef(BuildingType::SalvageBay);
+    b.outputBuffer.capacity =
+        (def && def->outputBufferCapacity) ? *def->outputBufferCapacity : 0;
+}
+
 std::vector<Port> BuildingSystem::computeInputPorts(const Building& b) const
 {
     // Build lookup sets for quick membership checks.
@@ -281,7 +394,7 @@ bool BuildingSystem::bodyCellsWithinWorldBounds(const std::vector<QPoint>& bodyC
                                                 QPoint anchor) const
 {
     const int heightTiles = m_config.world.heightTiles;
-    const int leftEdgeX   = -m_config.world.regions.asteroidWidth_tiles;
+    const int leftEdgeX   = -m_asteroidWidth_tiles;
     for (const QPoint& cell : bodyCells)
     {
         const QPoint worldCell = anchor + cell;
@@ -408,6 +521,18 @@ void BuildingSystem::setRecipe(BuildingId id, const std::string& recipeId)
     {
         if (site.id == id)
         {
+            // Auto-recipe buildings have no player-selected recipe
+            // (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING); ignore any attempt to set one.
+            if (isAutoRecipeBuildingType(site.type))
+            {
+                return;
+            }
+            // No-op if the recipe is unchanged, so a redundant selection does
+            // not wipe an already-configured ship layout.
+            if (site.recipeId == recipeId)
+            {
+                return;
+            }
             site.recipeId = recipeId;
             site.shipLayout = std::nullopt;
             return;
@@ -419,12 +544,30 @@ void BuildingSystem::setRecipe(BuildingId id, const std::string& recipeId)
     {
         if (building.id == id)
         {
+            // Auto-recipe buildings have no player-selected recipe
+            // (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING); ignore any attempt to set one.
+            if (isAutoRecipeBuildingType(building.type))
+            {
+                return;
+            }
+            // No-op if the recipe is unchanged, so a redundant selection does
+            // not wipe an already-configured ship layout or reset buffers.
+            if (building.recipeId == recipeId)
+            {
+                return;
+            }
             building.recipeId = recipeId;
             building.shipLayout = std::nullopt;
             building.inputBuffer.counts.clear();
             building.inputBuffer.caps.clear();
             building.outputBuffer.items.clear();
             building.outputBuffer.capacity = 0;
+            // Emerging items are part of the output buffer, so clearing it on a
+            // recipe change discards them too (REQ-MAT-OUTPUT-EMERGE); in-transit
+            // input items are discarded and their reservations released
+            // (REQ-MAT-INPUT-INTAKE).
+            for (std::vector<BeltItemSlot>& lane : building.emergingItems) { lane.clear(); }
+            for (std::vector<BeltItemSlot>& lane : building.incomingItems) { lane.clear(); }
             building.production = std::nullopt;
 
             if (!recipeId.empty())
@@ -471,6 +614,8 @@ void BuildingSystem::setShipLayout(BuildingId id, const ShipLayoutConfig& layout
             building.inputBuffer.caps.clear();
             building.outputBuffer.items.clear();
             building.outputBuffer.capacity = 0;
+            for (std::vector<BeltItemSlot>& lane : building.emergingItems) { lane.clear(); }
+            for (std::vector<BeltItemSlot>& lane : building.incomingItems) { lane.clear(); }
             if (!building.recipeId.empty() && building.type == BuildingType::Shipyard)
             {
                 initShipyardBuffers(building);
@@ -574,9 +719,21 @@ void BuildingSystem::tickConstruction(Tick currentTick)
         absPort.direction = port.direction;
         building.outputPorts.push_back(absPort);
     }
+    building.emergingItems.resize(building.outputPorts.size());
     building.inputPorts = computeInputPorts(building);
+    building.incomingItems.assign(building.inputPorts.size(), {});
 
-    if (!building.recipeId.empty())
+    if (building.type == BuildingType::SalvageBay)
+    {
+        initSalvageBayBuffer(building);
+    }
+    else if (isAutoRecipeBuildingType(building.type))
+    {
+        // Smelter/Reprocessing Plant need no recipe selection; buffers are set
+        // up from all recipes of the type (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING).
+        initAutoBuffers(building);
+    }
+    else if (!building.recipeId.empty())
     {
         if (building.type == BuildingType::Shipyard)
         {
@@ -637,79 +794,119 @@ void BuildingSystem::tickConstruction(Tick currentTick)
 void BuildingSystem::tickBeltPull()
 {
 	TRACE();
+    // Same per-tick step as the belts, so items travel inward at belt speed
+    // (REQ-GW-BELT-SPEED, REQ-MAT-INPUT-INTAKE).
+    const double progressPerTick = m_belts.getProgressPerTick_tpt();
+
     for (Building& building : m_buildings)
     {
-        // HQ: pull building_block items and add to global stock.
-        if (building.type == BuildingType::Hq)
+        const bool isHq = (building.type == BuildingType::Hq);
+
+        // 1. Advance every input belt and deliver arrivals (progress >= 0.5) into
+        //    the input buffer — or the global stock for the HQ. Runs for all
+        //    buildings so in-transit items keep moving even when feeding is gated
+        //    off, and arrivals become consumable before tickProduction (step 4).
+        for (std::size_t i = 0; i < building.incomingItems.size(); ++i)
         {
-            for (const Port& port : building.inputPorts)
+            std::vector<BeltItemSlot>& lane = building.incomingItems[i];
+            advanceBeltSlots(lane, progressPerTick);
+            while (!lane.empty() && lane.front().progress >= 0.5)
             {
-                const std::optional<ItemType> peeked = m_belts.peekItem(port);
-                if (peeked && peeked->id == "building_block")
+                const Item arrived = lane.front().item;
+                lane.erase(lane.begin());
+                if (isHq)
                 {
-                    const std::optional<Item> taken = m_belts.tryTakeItem(port);
-                    if (taken)
-                    {
-                        m_addBuildingBlocks(1);
-                    }
+                    m_addBuildingBlocks(1);
+                }
+                else
+                {
+                    building.inputBuffer.counts[arrived.type]++;
                 }
             }
-            continue;
         }
 
-        if (building.recipeId.empty())
+        // 2. Feed accepted items from adjacent belts onto the input belts at
+        //    progress 0.0. The acceptance rules — the HQ building-block case, the
+        //    required-input check, and the reservation — live in canAcceptInput so
+        //    direct coupling (REQ-MAT-DIRECT-COUPLE) shares them exactly.
+        for (std::size_t i = 0; i < building.inputPorts.size(); ++i)
         {
-            continue;
-        }
-
-        if (building.type != BuildingType::Shipyard)
-        {
-            const RecipeDef* recipe = findRecipe(building.recipeId, building.type);
-            if (!recipe || recipe->inputs.empty())
-            {
-                continue;
-            }
-        }
-
-        for (const Port& port : building.inputPorts)
-        {
-            const std::optional<ItemType> peeked = m_belts.peekItem(port);
-            if (!peeked)
-            {
-                continue;
-            }
-
-            const ItemType& type = *peeked;
-
-            // Accept only if this type is a required input and buffer has space.
-            const std::map<ItemType, int>::const_iterator capIt =
-                building.inputBuffer.caps.find(type);
-            if (capIt == building.inputBuffer.caps.end() || capIt->second == 0)
-            {
-                continue;
-            }
-
-            const int current = [&]() -> int
-            {
-                const std::map<ItemType, int>::const_iterator it =
-                    building.inputBuffer.counts.find(type);
-                return (it != building.inputBuffer.counts.end()) ? it->second : 0;
-            }();
-
-            if (current >= capIt->second)
-            {
-                continue;
-            }
-
-            const std::optional<Item> taken = m_belts.tryTakeItem(port);
+            const std::optional<ItemType> peeked = m_belts.peekItem(building.inputPorts[i]);
+            if (!peeked) { continue; }
+            if (!canAcceptInput(building, i, *peeked)) { continue; }
+            const std::optional<Item> taken = m_belts.tryTakeItem(building.inputPorts[i]);
             if (taken)
             {
-                building.inputBuffer.counts[taken->type]++;
+                depositToInputBelt(building, i, *taken);
             }
         }
     }
 }
 
+bool BuildingSystem::canAcceptInput(const Building& consumer,
+                                    std::size_t inputPortIndex,
+                                    const ItemType& type) const
+{
+    if (inputPortIndex >= consumer.incomingItems.size()) { return false; }
+    if (!inputLaneEntryFree(consumer.incomingItems[inputPortIndex])) { return false; }
+
+    // The HQ has no input buffer; it accepts building blocks into the global stock
+    // (REQ-HQ-BELT-INPUT) with no reservation.
+    if (consumer.type == BuildingType::Hq)
+    {
+        return type.id == "building_block";
+    }
+
+    // Everyone else: the item must be a required input whose reservation-aware
+    // buffer has room — buffered + in-transit below the cap (REQ-MAT-INPUT-INTAKE).
+    const std::map<ItemType, int>::const_iterator capIt =
+        consumer.inputBuffer.caps.find(type);
+    if (capIt == consumer.inputBuffer.caps.end() || capIt->second == 0)
+    {
+        return false;
+    }
+    return consumer.pendingInputCount(type) < capIt->second;
+}
+
+void BuildingSystem::depositToInputBelt(Building& consumer,
+                                        std::size_t inputPortIndex,
+                                        const Item& item)
+{
+    consumer.incomingItems[inputPortIndex].push_back(BeltItemSlot{item, 0.0});
+}
+
+bool BuildingSystem::tryDirectCoupleDeposit(BuildingId producerId,
+                                            const Port& outputPort,
+                                            const Item& item)
+{
+    const std::map<std::pair<int, int>, BuildingId>::const_iterator occIt =
+        m_tileOccupancy.find({outputPort.tile.x(), outputPort.tile.y()});
+    if (occIt == m_tileOccupancy.end() || occIt->second == producerId)
+    {
+        return false;
+    }
+
+    Building* consumer = findBuildingMutable(occIt->second);
+    if (!consumer)
+    {
+        return false;  // an unbuilt construction site, or not an operational building
+    }
+
+    // The coupling is the consumer input port meeting this output port: same flow
+    // direction, feeding the producer's output-port tile (REQ-MAT-DIRECT-COUPLE).
+    for (std::size_t j = 0; j < consumer->inputPorts.size(); ++j)
+    {
+        const Port& in = consumer->inputPorts[j];
+        if (in.direction != outputPort.direction) { continue; }
+        if (inputBodyTile(in.tile, in.direction) != outputPort.tile) { continue; }
+
+        if (!canAcceptInput(*consumer, j, item.type)) { return false; }
+        depositToInputBelt(*consumer, j, item);
+        return true;
+    }
+    return false;
+}
+
 void BuildingSystem::tickProduction(Tick currentTick)
 {
 	TRACE();
@@ -725,18 +922,15 @@ void BuildingSystem::tickProduction(Tick currentTick)
             continue;
         }
 
-        if (building.recipeId.empty())
+        const bool autoRecipe = isAutoRecipeBuildingType(building.type);
+        if (!autoRecipe && building.recipeId.empty())
         {
             continue;
         }
 
-        const RecipeDef* recipe = findRecipe(building.recipeId, building.type);
-        if (!recipe)
-        {
-            continue;
-        }
-
-        // If a production cycle is active, check for completion.
+        // If a production cycle is active, check for completion. Completion only
+        // needs the already-decided outputs, so it does not depend on which
+        // recipe is selected or auto-chosen.
         if (building.production)
         {
             if (currentTick >= building.production->completesAt)
@@ -752,66 +946,94 @@ void BuildingSystem::tickProduction(Tick currentTick)
             continue;
         }
 
-        // Idle: check if a new cycle can start.
-
-        // 1. All required inputs present?
-        bool inputsOk = true;
-        for (const RecipeIngredient& ing : recipe->inputs)
+        // Idle: gather the candidate recipes to try. Auto-recipe buildings
+        // (Smelter, Reprocessing Plant) have no selected recipe and try every
+        // recipe of their type in config order, running the first whose inputs
+        // are satisfied (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING). Other buildings
+        // try only their selected recipe.
+        std::vector<const RecipeDef*> candidates;
+        if (autoRecipe)
         {
-            const ItemType type{ing.item};
-            const std::map<ItemType, int>::const_iterator it =
-                building.inputBuffer.counts.find(type);
-            const int have = (it != building.inputBuffer.counts.end()) ? it->second : 0;
-            if (have < ing.amount)
+            for (const RecipeDef& r : m_config.recipes.recipes)
             {
-                inputsOk = false;
-                break;
-            }
-        }
-        if (!inputsOk)
-        {
-            continue;
-        }
-
-        // 2. Determine chosen outputs (roll for reprocessing).
-        std::vector<Item> chosen;
-        if (building.type == BuildingType::ReprocessingPlant)
-        {
-            chosen = rollReprocessingOutput(*recipe);
-            if (chosen.empty()) { continue; }
-        }
-        else
-        {
-            for (const RecipeOutput& out : recipe->outputs)
-            {
-                Item item;
-                item.type.id = out.item;
-                for (int i = 0; i < out.amount; ++i)
+                if (r.building == building.type && !r.inputs.empty())
                 {
-                    chosen.push_back(item);
+                    candidates.push_back(&r);
                 }
             }
         }
-
-        // 3. Output buffer has space for chosen outputs?
-        const int newSize = static_cast<int>(building.outputBuffer.items.size())
-                          + static_cast<int>(chosen.size());
-        if (newSize > building.outputBuffer.capacity)
+        else
         {
-            continue;
+            const RecipeDef* recipe = findRecipe(building.recipeId, building.type);
+            if (recipe)
+            {
+                candidates.push_back(recipe);
+            }
         }
 
-        // 4. Consume inputs and start cycle.
-        for (const RecipeIngredient& ing : recipe->inputs)
+        for (const RecipeDef* recipe : candidates)
         {
-            building.inputBuffer.counts[ItemType{ing.item}] -= ing.amount;
-        }
+            // 1. All required inputs present?
+            bool inputsOk = true;
+            for (const RecipeIngredient& ing : recipe->inputs)
+            {
+                const ItemType type{ing.item};
+                const std::map<ItemType, int>::const_iterator it =
+                    building.inputBuffer.counts.find(type);
+                const int have = (it != building.inputBuffer.counts.end()) ? it->second : 0;
+                if (have < ing.amount)
+                {
+                    inputsOk = false;
+                    break;
+                }
+            }
+            if (!inputsOk)
+            {
+                continue;
+            }
 
-        Production prod;
-        prod.recipeId     = building.recipeId;
-        prod.completesAt  = currentTick + secondsToTicks(recipe->durationSeconds);
-        prod.chosenOutputs = std::move(chosen);
-        building.production = std::move(prod);
+            // 2. Determine chosen outputs (roll for reprocessing).
+            std::vector<Item> chosen;
+            if (building.type == BuildingType::ReprocessingPlant)
+            {
+                chosen = rollReprocessingOutput(*recipe);
+                if (chosen.empty()) { continue; }
+            }
+            else
+            {
+                for (const RecipeOutput& out : recipe->outputs)
+                {
+                    Item item;
+                    item.type.id = out.item;
+                    for (int i = 0; i < out.amount; ++i)
+                    {
+                        chosen.push_back(item);
+                    }
+                }
+            }
+
+            // 3. Output buffer has space for chosen outputs? Emerging items still
+            //    count against the buffer (REQ-MAT-OUTPUT-EMERGE).
+            const int newSize = building.outputItemCount()
+                              + static_cast<int>(chosen.size());
+            if (newSize > building.outputBuffer.capacity)
+            {
+                continue;
+            }
+
+            // 4. Consume inputs and start cycle.
+            for (const RecipeIngredient& ing : recipe->inputs)
+            {
+                building.inputBuffer.counts[ItemType{ing.item}] -= ing.amount;
+            }
+
+            Production prod;
+            prod.recipeId      = recipe->id;
+            prod.completesAt   = currentTick + secondsToTicks(recipe->durationSeconds);
+            prod.chosenOutputs = std::move(chosen);
+            building.production = std::move(prod);
+            break;  // At most one cycle starts per tick.
+        }
     }
 }
 
@@ -843,7 +1065,16 @@ void BuildingSystem::tickShipyardProduction(Tick currentTick)
                 {
                     const Port& p = building.outputPorts[0];
                     const QVector2D spawnPos(p.tile.x() + 0.5f, p.tile.y() + 0.5f);
-                    m_spawnShip(building.recipeId, spawnPos, building.shipLayout);
+                    // A shipyard builds exactly what the player configured and
+                    // paid for. When no layout is set it produces a bare hull, so
+                    // pass an explicit empty layout rather than nullopt: the latter
+                    // would make ShipSystem fall back to the schematic's
+                    // defaultModules (a wave-only loadout) and yield free weapons.
+                    const std::optional<ShipLayoutConfig> layout =
+                        building.shipLayout.has_value()
+                            ? building.shipLayout
+                            : std::make_optional<ShipLayoutConfig>();
+                    m_spawnShip(building.recipeId, spawnPos, layout);
                 }
                 building.production = std::nullopt;
             }
@@ -917,31 +1148,97 @@ void BuildingSystem::tickShipyardProduction(Tick currentTick)
     }
 }
 
-void BuildingSystem::tickBeltPush()
+void BuildingSystem::tickOutputBelts()
 {
 	TRACE();
+    // Use BeltSystem's own per-tick step so emerging items travel at exactly the
+    // same speed as real belts (REQ-GW-BELT-SPEED, REQ-MAT-OUTPUT-EMERGE).
+    const double progressPerTick = m_belts.getProgressPerTick_tpt();
+
     for (Building& building : m_buildings)
     {
-        if (building.outputBuffer.items.empty())
+        for (std::size_t p = 0; p < building.outputPorts.size(); ++p)
         {
-            continue;
-        }
+            const Port& port = building.outputPorts[p];
+            std::vector<BeltItemSlot>& lane = building.emergingItems[p];
 
-        for (const Port& outputPort : building.outputPorts)
-        {
-            if (building.outputBuffer.items.empty())
+            // 1. Advance emerging items using the shared belt packing (progress
+            //    caps to 0.5 / 0.75 / 1.0 for up to three items).
+            advanceBeltSlots(lane, progressPerTick);
+
+            // 2. Hand the front item off once it reaches the output edge (progress
+            //    1.0): onto the adjacent real belt, or — if a building's input edge
+            //    meets this port — straight into that building (REQ-MAT-DIRECT-COUPLE).
+            //    On refusal (no belt/coupling, output-edge per REQ-MAT-ACCEPT-DIR, or
+            //    a full target) it stays stuck at 1.0.
+            if (!lane.empty() && lane.front().progress >= 1.0)
             {
-                break;
+                const Item item = lane.front().item;
+                if (m_belts.tryPutItem(port.tile, item, port.direction)
+                    || tryDirectCoupleDeposit(building.id, port, item))
+                {
+                    lane.erase(lane.begin());
+                }
             }
-            const Item item = building.outputBuffer.items.front();
-            if (m_belts.tryPutItem(outputPort.tile, item, outputPort.direction))
+
+            // 3. Feed the next buffered item onto the lane at progress 0.5 when the
+            //    entry slot is free — the lane holds at most three items and a new
+            //    one needs a quarter-tile clearance ahead of 0.5.
+            if (!building.outputBuffer.items.empty()
+                && lane.size() < 3
+                && (lane.empty() || lane.back().progress >= 0.75))
             {
+                lane.push_back(BeltItemSlot{building.outputBuffer.items.front(), 0.5});
                 building.outputBuffer.items.erase(building.outputBuffer.items.begin());
             }
         }
     }
 }
 
+void BuildingSystem::forEachEmergingItem(
+    const std::function<void(const ItemType&, QPointF)>& visit) const
+{
+    for (const Building& building : m_buildings)
+    {
+        for (std::size_t p = 0; p < building.outputPorts.size(); ++p)
+        {
+            const Port& port = building.outputPorts[p];
+            const QPoint bodyTile = outputBodyTile(port.tile, port.direction);
+            const std::vector<BeltItemSlot>& lane = building.emergingItems[p];
+
+            // Render least-progressed first (bottom) → most-progressed last (top),
+            // matching belt item ordering (REQ-GW-TILE-SIZE).
+            for (int i = static_cast<int>(lane.size()) - 1; i >= 0; --i)
+            {
+                visit(lane[i].item.type,
+                      beltSlotWorldPos(bodyTile, port.direction, lane[i].progress));
+            }
+        }
+    }
+}
+
+void BuildingSystem::forEachIncomingItem(
+    const std::function<void(const ItemType&, QPointF)>& visit) const
+{
+    for (const Building& building : m_buildings)
+    {
+        for (std::size_t p = 0; p < building.inputPorts.size(); ++p)
+        {
+            const Port& port = building.inputPorts[p];
+            const QPoint bodyTile = inputBodyTile(port.tile, port.direction);
+            const std::vector<BeltItemSlot>& lane = building.incomingItems[p];
+
+            // Render least-progressed first (bottom) → most-progressed last (top),
+            // matching belt item ordering (REQ-GW-TILE-SIZE).
+            for (int i = static_cast<int>(lane.size()) - 1; i >= 0; --i)
+            {
+                visit(lane[i].item.type,
+                      beltSlotWorldPos(bodyTile, port.direction, lane[i].progress));
+            }
+        }
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Queries
 // ---------------------------------------------------------------------------
@@ -958,6 +1255,18 @@ const Building* BuildingSystem::findBuilding(BuildingId id) const
     return nullptr;
 }
 
+Building* BuildingSystem::findBuildingMutable(BuildingId id)
+{
+    for (Building& building : m_buildings)
+    {
+        if (building.id == id)
+        {
+            return &building;
+        }
+    }
+    return nullptr;
+}
+
 const ConstructionSite* BuildingSystem::findSite(BuildingId id) const
 {
     for (const ConstructionSite& site : m_constructionQueue)
@@ -1131,7 +1440,14 @@ void BuildingSystem::rotateInPlace(BuildingId id, Rotation newRotation)
             absPort.direction = port.direction;
             b.outputPorts.push_back(absPort);
         }
+        // The output ports moved; discard any in-flight emerging items and re-size
+        // the lanes to the new port set (REQ-MAT-OUTPUT-EMERGE).
+        b.emergingItems.clear();
+        b.emergingItems.resize(b.outputPorts.size());
         b.inputPorts = computeInputPorts(b);
+        // Likewise discard in-transit input items and re-size the input belts to
+        // the new port set (REQ-MAT-INPUT-INTAKE).
+        b.incomingItems.assign(b.inputPorts.size(), {});
 
         // Re-register with BeltSystem (items on tile are discarded).
         if (b.type == BuildingType::Belt)
@@ -1200,7 +1516,9 @@ bool BuildingSystem::deliverScrapToSalvageBay(BuildingId bayId)
     {
         return false;
     }
-    if (static_cast<int>(bay->outputBuffer.items.size()) >= bay->outputBuffer.capacity)
+    // Emerging scrap still counts against the bay's holding capacity
+    // (REQ-MAT-OUTPUT-EMERGE).
+    if (bay->outputItemCount() >= bay->outputBuffer.capacity)
     {
         return false;
     }
@@ -1235,7 +1553,14 @@ BuildingId BuildingSystem::placeImmediate(BuildingType type,
         absPort.direction = port.direction;
         building.outputPorts.push_back(absPort);
     }
+    building.emergingItems.resize(building.outputPorts.size());
     building.inputPorts = computeInputPorts(building);
+    building.incomingItems.assign(building.inputPorts.size(), {});
+
+    if (type == BuildingType::SalvageBay)
+    {
+        initSalvageBayBuffer(building);
+    }
 
     m_buildings.push_back(std::move(building));
     return id;
@@ -1336,6 +1661,26 @@ void BuildingSystem::appendChecksum(Hasher& hasher) const
         appendInputBuffer(hasher, b.inputBuffer);
         appendItems(hasher, b.outputBuffer.items);
         hasher.append(b.outputBuffer.capacity);
+        hasher.append(b.emergingItems.size());
+        for (const std::vector<BeltItemSlot>& lane : b.emergingItems)
+        {
+            hasher.append(lane.size());
+            for (const BeltItemSlot& slot : lane)
+            {
+                hasher.append(slot.item.type.id);
+                hasher.append(slot.progress);
+            }
+        }
+        hasher.append(b.incomingItems.size());
+        for (const std::vector<BeltItemSlot>& lane : b.incomingItems)
+        {
+            hasher.append(lane.size());
+            for (const BeltItemSlot& slot : lane)
+            {
+                hasher.append(slot.item.type.id);
+                hasher.append(slot.progress);
+            }
+        }
         hasher.append(b.production.has_value());
         if (b.production.has_value())
         {

src/lib/sim/BuildingSystem.h

@@ -10,6 +10,7 @@
 #include <vector>
 
 #include <QPoint>
+#include <QPointF>
 #include <QVector2D>
 
 #include "BeltSystem.h"
@@ -59,6 +60,11 @@ public:
     bool isPlacementValid(BuildingType type, QPoint anchor,
                           Rotation rotation) const;
 
+    // Sets the current buildable asteroid width in tiles. Grows the left
+    // placement bound as the player unlocks asteroid expansions (REQ-EXP-UNLOCK).
+    // Defaults to world.regions.asteroid_width_tiles at construction.
+    void setAsteroidWidth_tiles(int widthTiles) { m_asteroidWidth_tiles = widthTiles; }
+
     // Remove a building or construction site by id.  Returns the refund in
     // building blocks (floor(cost * refundPercentage / 100)).  Returns 0 for
     // unknown ids.
@@ -89,7 +95,10 @@ public:
     void tickBeltPull();
     void tickProduction(Tick currentTick);
     void tickShipyardProduction(Tick currentTick);
-    void tickBeltPush();
+    // Advances each building's virtual output belts, hands finished items off onto
+    // the adjacent real belt, and feeds new buffered items into them
+    // (REQ-MAT-OUTPUT-EMERGE).
+    void tickOutputBelts();
 
     // -- Queries -------------------------------------------------------------
     struct BeltTileInfo
@@ -116,6 +125,19 @@ public:
     std::vector<BeltTileInfo> allBeltTiles()             const;
     bool                      isTileOccupied(QPoint tile) const;
 
+    // Visits every item currently emerging from a building output port on its
+    // virtual output belt (REQ-MAT-OUTPUT-EMERGE), passing the item type and its
+    // world-space centre (in tile units). Least-progressed first (drawn bottom) so
+    // callers can paint in visit order (REQ-GW-TILE-SIZE ordering).
+    void forEachEmergingItem(
+        const std::function<void(const ItemType&, QPointF)>& visit) const;
+
+    // Visits every item currently travelling inward on a building input port's
+    // virtual input belt (REQ-MAT-INPUT-INTAKE), passing the item type and its
+    // world-space centre (in tile units). Least-progressed first (drawn bottom).
+    void forEachIncomingItem(
+        const std::function<void(const ItemType&, QPointF)>& visit) const;
+
     // Returns the entity id of the building or construction site whose footprint
     // exactly coincides with the ghost (type, anchor, rot) and is of the same
     // building type.  Returns nullopt otherwise.
@@ -159,12 +181,36 @@ public:
     void appendChecksum(Hasher& hasher) const;
 
 private:
+    Building*            findBuildingMutable(BuildingId id);
+    // True if the consumer would accept `type` at the given input port right now:
+    // it is a required input (or a building block for the HQ), the reservation-aware
+    // buffer has room, and the input belt entry is free (REQ-MAT-INPUT-INTAKE).
+    bool                 canAcceptInput(const Building& consumer,
+                                        std::size_t inputPortIndex,
+                                        const ItemType& type) const;
+    // Places an accepted item onto the consumer's input belt at progress 0.0,
+    // reserving a per-material buffer slot (REQ-MAT-INPUT-INTAKE).
+    void                 depositToInputBelt(Building& consumer,
+                                            std::size_t inputPortIndex,
+                                            const Item& item);
+    // Attempts to hand an emerging output item straight into a directly adjacent
+    // building whose input edge meets the producer's output port (REQ-MAT-DIRECT-COUPLE).
+    // Returns true if the item was accepted onto the consumer's input belt.
+    bool                 tryDirectCoupleDeposit(BuildingId producerId,
+                                                const Port& outputPort,
+                                                const Item& item);
+
     const BuildingDef*  findBuildingDef(BuildingType type) const;
     const RecipeDef*    findRecipe(const std::string& id, BuildingType type) const;
     const ShipDef*      findShipDef(const std::string& id) const;
     const ModuleDef*    findModuleDef(const std::string& id) const;
     void                initBuffers(Building& b, const RecipeDef& recipe) const;
+    // Buffers for an auto-recipe building (Smelter, Reprocessing Plant): input
+    // caps span the union of every recipe of the building's type; no player
+    // recipe is selected (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING).
+    void                initAutoBuffers(Building& b) const;
     void                initShipyardBuffers(Building& b) const;
+    void                initSalvageBayBuffer(Building& b) const;
     std::vector<Port>   computeInputPorts(const Building& b) const;
     std::vector<Item>   rollReprocessingOutput(const RecipeDef& recipe);
     bool                bodyCellsWithinWorldBounds(
@@ -179,6 +225,7 @@ private:
                        const std::optional<ShipLayoutConfig>&)> m_spawnShip;
     std::function<bool(const std::string&)>        m_isItemUnlocked;
     std::mt19937&                                  m_rng;
+    int                                            m_asteroidWidth_tiles;
 
     std::vector<Building>           m_buildings;
     std::deque<ConstructionSite>    m_constructionQueue;

src/lib/sim/CMakeLists.txt

@@ -8,8 +8,10 @@ SET(HDRS
     ${CMAKE_CURRENT_SOURCE_DIR}/ReplayReader.h
     ${CMAKE_CURRENT_SOURCE_DIR}/ReplayPlayer.h
     ${CMAKE_CURRENT_SOURCE_DIR}/TickDriver.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/BeltSlot.h
     ${CMAKE_CURRENT_SOURCE_DIR}/BeltSystem.h
     ${CMAKE_CURRENT_SOURCE_DIR}/Building.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/BuildingConfig.h
     ${CMAKE_CURRENT_SOURCE_DIR}/BuildingSystem.h
     ${CMAKE_CURRENT_SOURCE_DIR}/EntityHitTest.h
     ${CMAKE_CURRENT_SOURCE_DIR}/ShipLayout.h
@@ -30,7 +32,9 @@ SET(SRCS
     ${CMAKE_CURRENT_SOURCE_DIR}/ReplayReader.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/ReplayPlayer.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/TickDriver.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/BeltSlot.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/BeltSystem.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/BuildingConfig.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/BuildingSystem.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/EntityHitTest.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/ShipStatsCalculator.cpp

src/lib/sim/Command.h

@@ -35,6 +35,7 @@ enum class CommandKind
     SetSplitterFilters,
     ClearBeltTiles,
     ApplySchematicChoice,
+    ExpandAsteroid,
     Reset
 };
 
@@ -129,6 +130,14 @@ struct ApplySchematicChoiceCommand : Command
     int choiceIndex = 0;
 };
 
+// Unlocks the next asteroid expansion (REQ-EXP-UNLOCK). Carries no payload: the
+// simulation derives the cost and column count from its own expansion counter
+// and config, so a recorded command replays identically.
+struct ExpandAsteroidCommand : Command
+{
+    ExpandAsteroidCommand() : Command(CommandKind::ExpandAsteroid) {}
+};
+
 // Restart boundary: reinitializes the simulation with a fresh seed and, if
 // config is set, a reloaded config (GameConfig is move-only, so it is carried by
 // shared_ptr and moved into the sim on apply). A null config keeps the current

src/lib/sim/EntityHitTest.cpp

@@ -1,9 +1,11 @@
 #include "EntityHitTest.h"
 
+#include <algorithm>
 #include <cmath>
 
 #include "EntityAdmin.h"
 #include "PositionComponent.h"
+#include "ScrapDataComponent.h"
 #include "StationBodyComponent.h"
 #include "HealthComponent.h"
 
@@ -54,3 +56,48 @@ entt::entity entityAtWorldPos(EntityAdmin& admin, QVector2D worldPos)
 
     return bestShip;
 }
+
+entt::entity scrapAtWorldPos(EntityAdmin& admin, QVector2D worldPos)
+{
+    // Slightly larger than the scrap's rendered radius (0.2 tiles) so small piles
+    // remain easy to click; tunable.
+    constexpr float kScrapHitRadiusSquared = 0.35f * 0.35f;
+    entt::entity bestScrap = entt::null;
+    float bestDistSquared = kScrapHitRadiusSquared;
+
+    admin.forEach<ScrapDataComponent, PositionComponent>(
+        [&](entt::entity entity, const ScrapDataComponent& /*sd*/, const PositionComponent& pos)
+        {
+            const float dx = pos.value.x() - worldPos.x();
+            const float dy = pos.value.y() - worldPos.y();
+            const float distSquared = dx * dx + dy * dy;
+            if (distSquared < bestDistSquared)
+            {
+                bestDistSquared = distSquared;
+                bestScrap = entity;
+            }
+        });
+
+    return bestScrap;
+}
+
+std::vector<entt::entity> scrapInBox(EntityAdmin& admin, QPoint tileA, QPoint tileB)
+{
+    const int minX = std::min(tileA.x(), tileB.x());
+    const int maxX = std::max(tileA.x(), tileB.x());
+    const int minY = std::min(tileA.y(), tileB.y());
+    const int maxY = std::max(tileA.y(), tileB.y());
+
+    std::vector<entt::entity> result;
+    admin.forEach<ScrapDataComponent, PositionComponent>(
+        [&](entt::entity entity, const ScrapDataComponent& /*sd*/, const PositionComponent& pos)
+        {
+            const int tileX = static_cast<int>(std::floor(pos.value.x()));
+            const int tileY = static_cast<int>(std::floor(pos.value.y()));
+            if (tileX >= minX && tileX <= maxX && tileY >= minY && tileY <= maxY)
+            {
+                result.push_back(entity);
+            }
+        });
+    return result;
+}

src/lib/sim/EntityHitTest.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <vector>
+
+#include <QPoint>
 #include <QVector2D>
 
 #include "entt/entity/entity.hpp"
@@ -7,3 +10,12 @@
 class EntityAdmin;
 
 entt::entity entityAtWorldPos(EntityAdmin& admin, QVector2D worldPos);
+
+// Returns the nearest scrap pile whose center is within the scrap pick radius of
+// worldPos, or entt::null if none (REQ-UI-SCRAP-CLICK-SELECT). Scrap is picked only
+// after actors: entityAtWorldPos never returns scrap (scrap has no HealthComponent).
+entt::entity scrapAtWorldPos(EntityAdmin& admin, QVector2D worldPos);
+
+// Returns every scrap pile whose position falls within the inclusive tile rectangle
+// spanned by tileA and tileB, in any corner order (REQ-UI-SCRAP-MULTI-SELECT).
+std::vector<entt::entity> scrapInBox(EntityAdmin& admin, QPoint tileA, QPoint tileB);

src/lib/sim/Simulation.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cmath>
 
 #include "AiSystem.h"
 #include "Command.h"
@@ -132,6 +133,7 @@ void Simulation::reset(unsigned int seed)
     m_nextDepartureTick        = secondsToTicks(m_config.world.departureIntervalSeconds);
     m_nextBuildingId                   = 1;
     m_buildingBlocksStock      = m_config.world.startingBuildingBlocks;
+    m_expansionsPurchased      = 0;
     m_gameOver                      = false;
     m_isWon                         = false;
     m_artifactCount                 = 0;
@@ -275,6 +277,9 @@ void Simulation::apply(const Command& command)
     case CommandKind::ApplySchematicChoice:
         applySchematicChoice(static_cast<const ApplySchematicChoiceCommand&>(command).choiceIndex);
         break;
+    case CommandKind::ExpandAsteroid:
+        tryExpandAsteroid();
+        break;
     case CommandKind::Reset:
     {
         const ResetCommand& c = static_cast<const ResetCommand&>(command);
@@ -310,7 +315,7 @@ void Simulation::tick()
     m_buildingSystem->tickBeltPull();                    // step 3
     m_buildingSystem->tickProduction(m_currentTick);     // step 4
     m_buildingSystem->tickShipyardProduction(m_currentTick); // step 4b
-    m_buildingSystem->tickBeltPush();                    // step 5
+    m_buildingSystem->tickOutputBelts();                 // step 5
     m_beltSystem.tick();                                 // step 6
 
     // Step 7: ship behavior systems (movement arbitration via intent priority)
@@ -635,12 +640,14 @@ void Simulation::generateSchematicChoices(int destroyedStationLevel)
     {
         if (def.unlockAtStationLevel < 0 || def.unlockAtStationLevel > destroyedStationLevel) { continue; }
         if (m_schematicLevels.at(def.id).unlocked) { continue; }
+        if (!prerequisitesSatisfied(def.unlockRequires)) { continue; }
         pool.push_back({def.id, DropType::Ship});
     }
     for (const ModuleDef& def : m_config.modules.modules)
     {
         if (def.unlockAtStationLevel < 0 || def.unlockAtStationLevel > destroyedStationLevel) { continue; }
         if (m_moduleSchematicLevels.at(def.id).unlocked) { continue; }
+        if (!prerequisitesSatisfied(def.unlockRequires)) { continue; }
         pool.push_back({def.id, DropType::Module});
     }
     for (const RecipeDef& def : m_config.recipes.recipes)
@@ -656,6 +663,7 @@ void Simulation::generateSchematicChoices(int destroyedStationLevel)
             if (m_unlockedItemIds.count(out.item) > 0) { outputUnlocked = true; break; }
         }
         if (!outputUnlocked) { continue; }
+        if (!prerequisitesSatisfied(def.unlockRequires)) { continue; }
         pool.push_back({def.id, DropType::Recipe});
     }
 
@@ -699,14 +707,7 @@ void Simulation::generateSchematicChoices(int destroyedStationLevel)
         else
         {
             option.type = SchematicType::Recipe;
-            for (const RecipeDef& def : m_config.recipes.recipes)
-            {
-                if (def.id == entry.id && !def.outputs.empty())
-                {
-                    option.displayName = toDisplayName(def.outputs[0].item);
-                    break;
-                }
-            }
+            option.displayName = toDisplayName(entry.id);
         }
 
         // REQ-DEF-SCHEMATIC-DROP: preview recipes newly implicitly unlocked by this option.
@@ -729,7 +730,7 @@ void Simulation::generateSchematicChoices(int destroyedStationLevel)
 
         const UnlockedSets hypothetical = computeUnlockedSets(
             hypotheticalShipIds, hypotheticalModuleIds, hypotheticalRecipeSchematicIds);
-        option.newlyUnlockedItemNames = computeNewlyUnlockedItemNames(hypothetical);
+        option.newlyUnlockedRecipeIds = computeNewlyUnlockedRecipeIds(hypothetical);
 
         m_pendingSchematicChoices.push_back(option);
     }
@@ -808,6 +809,32 @@ std::set<std::string> Simulation::getUnlockedModuleSchematicIds() const
     return ids;
 }
 
+bool Simulation::isSchematicIdExplicitlyUnlocked(const std::string& schematicId) const
+{
+    // A prerequisite is satisfied only by an explicitly-unlocked schematic
+    // (REQ-LOCK-PREREQ): a ship or module schematic marked unlocked, or a recipe
+    // schematic in the explicit-unlock set. Cross-type ids are looked up with
+    // find/count so an id from one namespace never throws against another.
+    const std::map<std::string, SchematicState>::const_iterator shipIt =
+        m_schematicLevels.find(schematicId);
+    if (shipIt != m_schematicLevels.end() && shipIt->second.unlocked) { return true; }
+
+    const std::map<std::string, SchematicState>::const_iterator moduleIt =
+        m_moduleSchematicLevels.find(schematicId);
+    if (moduleIt != m_moduleSchematicLevels.end() && moduleIt->second.unlocked) { return true; }
+
+    return m_unlockedRecipeSchematicIds.count(schematicId) > 0;
+}
+
+bool Simulation::prerequisitesSatisfied(const std::vector<std::string>& unlockRequires) const
+{
+    for (const std::string& requiredId : unlockRequires)
+    {
+        if (!isSchematicIdExplicitlyUnlocked(requiredId)) { return false; }
+    }
+    return true;
+}
+
 Simulation::UnlockedSets Simulation::computeUnlockedSets(
     const std::set<std::string>& unlockedShipSchematicIds,
     const std::set<std::string>& unlockedModuleSchematicIds,
@@ -891,23 +918,20 @@ Simulation::UnlockedSets Simulation::computeUnlockedSets(
     return result;
 }
 
-std::vector<std::string> Simulation::computeNewlyUnlockedItemNames(const UnlockedSets& hypothetical) const
+std::vector<std::string> Simulation::computeNewlyUnlockedRecipeIds(const UnlockedSets& hypothetical) const
 {
-    std::set<std::string> itemNames;
+    std::vector<std::string> recipeIds;
     for (const std::string& recipeId : hypothetical.recipeIds)
     {
         if (m_unlockedRecipeIds.count(recipeId) > 0) { continue; }
-        for (const RecipeDef& def : m_config.recipes.recipes)
-        {
-            if (def.id != recipeId) { continue; }
-            for (const RecipeOutput& out : def.outputs)
-            {
-                itemNames.insert(toDisplayName(out.item));
-            }
-            break;
-        }
+        recipeIds.push_back(recipeId);
     }
-    return std::vector<std::string>(itemNames.begin(), itemNames.end());
+    std::sort(recipeIds.begin(), recipeIds.end(),
+              [](const std::string& lhs, const std::string& rhs)
+              {
+                  return toDisplayName(lhs) < toDisplayName(rhs);
+              });
+    return recipeIds;
 }
 
 bool Simulation::isRecipeUnlocked(const std::string& recipeId) const
@@ -964,6 +988,7 @@ unsigned long long Simulation::computeStateChecksum() const
     hasher.append(m_gameOver);
     hasher.append(m_isWon);
     hasher.append(m_artifactCount);
+    hasher.append(m_expansionsPurchased);
 
     // WaveSystem scalar state, reached through existing accessors.
     hasher.append(threatLevel());
@@ -1071,6 +1096,31 @@ int Simulation::buildingBlocksStock() const
     return m_buildingBlocksStock;
 }
 
+int Simulation::currentAsteroidWidth_tiles() const
+{
+    return m_config.world.regions.asteroidWidth_tiles
+        + m_expansionsPurchased * m_config.world.expansion.columnsPerExpansion_tiles;
+}
+
+int Simulation::currentExpansionCost() const
+{
+    const double cost = m_config.world.expansion.costBuildingBlocksFormula.evaluate(
+        static_cast<double>(m_expansionsPurchased));
+    return static_cast<int>(std::floor(cost));
+}
+
+void Simulation::tryExpandAsteroid()
+{
+    const int cost = currentExpansionCost();
+    if (m_buildingBlocksStock < cost)
+    {
+        return;
+    }
+    m_buildingBlocksStock -= cost;
+    ++m_expansionsPurchased;
+    m_buildingSystem->setAsteroidWidth_tiles(currentAsteroidWidth_tiles());
+}
+
 bool Simulation::isGameOver() const
 {
     return m_gameOver;

src/lib/sim/Simulation.h

@@ -72,6 +72,12 @@ public:
     // The seed this run was (re)initialized with; written to the replay header.
     unsigned int getSeed()        const;
     int    buildingBlocksStock()  const;
+    // Current asteroid width in tiles = base width + purchased expansions
+    // (REQ-EXP-UNLOCK, REQ-GW-ASTEROID-EXPAND).
+    int    currentAsteroidWidth_tiles() const;
+    // Building block cost of the next expansion, floored to an integer
+    // (REQ-EXP-COST); x = number of expansions already purchased.
+    int    currentExpansionCost()  const;
     bool   isGameOver()           const;
     bool   isWon()                const;
     int    artifactCount()        const;
@@ -136,6 +142,11 @@ private:
     // Clears the pending choices after application.
     void applySchematicChoice(int choiceIndex);
 
+    // Unlocks one asteroid expansion if affordable (REQ-EXP-UNLOCK): checks the
+    // current cost against the stock, deducts it, increments the expansion
+    // counter, and widens the buildable asteroid. No-op if blocks are short.
+    void tryExpandAsteroid();
+
     // Mutable subsystem accessors; same chokepoint rule as the mutators above.
     BuildingSystem&       buildingsMutable();
     BeltSystem&           beltsMutable();
@@ -165,6 +176,7 @@ private:
     Tick     m_nextDepartureTick;
     BuildingId m_nextBuildingId;
     int      m_buildingBlocksStock;
+    int      m_expansionsPurchased = 0;  // REQ-EXP-COST formula variable x
     bool     m_gameOver    = false;
     bool     m_isWon       = false;
     int      m_artifactCount = 0;
@@ -215,9 +227,15 @@ private:
     std::set<std::string> getUnlockedShipSchematicIds() const;
     std::set<std::string> getUnlockedModuleSchematicIds() const;
 
-    // Display names (deduplicated, alphabetical) of output items of recipes in
+    // True if schematicId names a currently explicitly-unlocked ship, module, or
+    // assembler recipe schematic (REQ-LOCK-PREREQ satisfaction basis).
+    bool isSchematicIdExplicitlyUnlocked(const std::string& schematicId) const;
+    // True if every prerequisite in unlockRequires is explicitly unlocked (REQ-LOCK-PREREQ).
+    bool prerequisitesSatisfied(const std::vector<std::string>& unlockRequires) const;
+
+    // Ids (sorted alphabetically by display name) of the recipes in
     // hypothetical.recipeIds that are not yet in m_unlockedRecipeIds.
-    std::vector<std::string> computeNewlyUnlockedItemNames(const UnlockedSets& hypothetical) const;
+    std::vector<std::string> computeNewlyUnlockedRecipeIds(const UnlockedSets& hypothetical) const;
 
     EntityAdmin                       m_admin;
     BeltSystem                        m_beltSystem;

src/lib/sim/ThreatCostCalculator.cpp

@@ -30,6 +30,7 @@ double computeMaterialThreat(const ThreatCostTable& table,
     return total;
 }
 
+// Returns true if every input of the recipe has a resolved threat value.
 bool allInputsResolved(const RecipeDef& recipe,
                        const std::map<std::string, double>& resolved)
 {
@@ -43,15 +44,18 @@ bool allInputsResolved(const RecipeDef& recipe,
     return true;
 }
 
-double computeRecipeThreat(const RecipeDef& recipe,
-                           const std::map<std::string, double>& resolved)
+// Computes the raw recipe threat (duration + sum of input threats × amounts),
+// divided by the output amount to get the per-unit threat.
+double computeRecipeThreatPerUnit(const RecipeDef& recipe,
+                                  int outputAmount,
+                                  const std::map<std::string, double>& resolved)
 {
     double threat = recipe.durationSeconds;
     for (const RecipeIngredient& input : recipe.inputs)
     {
         threat += resolved.at(input.item) * input.amount;
     }
-    return threat;
+    return threat / static_cast<double>(outputAmount);
 }
 
 }  // namespace
@@ -69,118 +73,259 @@ ThreatCostTable computeThreatCostTable(const GameConfig& config)
         ? 1.0 / config.world.scrapPerThreat
         : 0.0;
 
-    // Build lookup: output item → non-reprocessing recipes and reprocessing recipes.
-    std::map<std::string, std::vector<RecipeRef>> nonReprocessingRecipes;
+    // -------------------------------------------------------------------------
+    // Build per-item recipe lookup tables.
+    // -------------------------------------------------------------------------
+
+    // Items that have at least one non-reprocessing recipe that does NOT consume
+    // scrap — these items' scrap-consuming recipes are excluded from threat
+    // computation (REQ-THREAT-ITEM: scrap-consuming recipes are a fallback only).
+    std::set<std::string> scrapFreeItems;
+
+    // nonReprocessingRecipes: item → all eligible non-reprocessing (recipe, output)
+    // pairs. Scrap-consuming recipes are collected here temporarily; they are
+    // filtered out per item after we know which items have a scrap-free producer.
+    struct EligiblePair
+    {
+        const RecipeDef* recipe;
+        int outputAmount;
+        bool consumesScrap;
+    };
+    std::map<std::string, std::vector<EligiblePair>> nonReprocessingCandidates;
+
+    // reprocessingRecipes: item → all reprocessing-recipe refs (probability
+    // values are raw from config; we normalize them per-recipe below).
     std::map<std::string, std::vector<RecipeRef>> reprocessingRecipes;
 
     for (const RecipeDef& recipe : config.recipes.recipes)
     {
         if (recipe.building == BuildingType::ReprocessingPlant)
         {
+            // Compute the total weight across all outputs of this reprocessing recipe
+            // so we can normalize each output's probability.
+            double totalWeight = 0.0;
+            for (const RecipeOutput& out : recipe.outputs)
+            {
+                totalWeight += out.probability.value_or(1.0);
+            }
+            if (totalWeight <= 0.0)
+            {
+                continue;
+            }
+
             for (const RecipeOutput& out : recipe.outputs)
             {
                 RecipeRef ref;
                 ref.recipe = &recipe;
                 ref.outputItem = out.item;
                 ref.outputAmount = out.amount;
-                ref.probability = out.probability.value_or(1.0);
+                ref.probability = out.probability.value_or(1.0) / totalWeight;
                 reprocessingRecipes[out.item].push_back(ref);
             }
         }
         else
         {
+            // Check whether this non-reprocessing recipe consumes scrap.
+            bool consumesScrap = false;
+            for (const RecipeIngredient& input : recipe.inputs)
+            {
+                if (input.item == "scrap")
+                {
+                    consumesScrap = true;
+                    break;
+                }
+            }
+
             for (const RecipeOutput& out : recipe.outputs)
             {
-                RecipeRef ref;
-                ref.recipe = &recipe;
-                ref.outputItem = out.item;
-                ref.outputAmount = out.amount;
-                ref.probability = 1.0;
-                nonReprocessingRecipes[out.item].push_back(ref);
+                if (!consumesScrap)
+                {
+                    scrapFreeItems.insert(out.item);
+                }
+
+                EligiblePair pair;
+                pair.recipe = &recipe;
+                pair.outputAmount = out.amount;
+                pair.consumesScrap = consumesScrap;
+                nonReprocessingCandidates[out.item].push_back(pair);
             }
         }
     }
 
-    // Collect all item names that need resolving.
-    std::set<std::string> unresolved;
-    for (const std::pair<const std::string, std::vector<RecipeRef>>& entry : nonReprocessingRecipes)
+    // Filter nonReprocessingCandidates: for items that have at least one
+    // scrap-free producer, drop their scrap-consuming recipes.
+    // Build the final per-item list of (recipe, outputAmount) pairs eligible
+    // for the max-across-recipes rule (REQ-THREAT-ITEM).
+    std::map<std::string, std::vector<std::pair<const RecipeDef*, int>>> eligibleRecipes;
+    for (std::map<std::string, std::vector<EligiblePair>>::const_iterator it =
+             nonReprocessingCandidates.begin();
+         it != nonReprocessingCandidates.end();
+         ++it)
     {
-        unresolved.insert(entry.first);
-    }
-    for (const std::pair<const std::string, std::vector<RecipeRef>>& entry : reprocessingRecipes)
-    {
-        unresolved.insert(entry.first);
+        const std::string& item = it->first;
+        const std::vector<EligiblePair>& candidates = it->second;
+        bool hasScrapFree = (scrapFreeItems.find(item) != scrapFreeItems.end());
+
+        for (const EligiblePair& candidate : candidates)
+        {
+            if (candidate.consumesScrap && hasScrapFree)
+            {
+                // Scrap-consuming recipe excluded: item has a scrap-free producer.
+                continue;
+            }
+            eligibleRecipes[item].emplace_back(candidate.recipe, candidate.outputAmount);
+        }
     }
 
-    // Iteratively resolve non-reprocessing items.
-    bool progress = true;
-    while (progress)
+    // -------------------------------------------------------------------------
+    // Resolution: seed resolved map with scrap, then alternate the
+    // non-reprocessing pass and the reprocessing pass to a fixpoint.
+    // Fix (8): iterate until neither pass makes progress, rather than running
+    // the reprocessing pass once at the end.
+    // -------------------------------------------------------------------------
+
+    std::map<std::string, double>& resolved = table.itemThreat;
+    resolved["scrap"] = table.scrapThreat;
+
+    // Non-reprocessing resolution pass.
+    // Fix (9): commit an item only when EVERY eligible recipe for it is
+    // computable, not just the first one that resolves. This ensures a shallow
+    // shortcut recipe cannot undercut a deeper base recipe by resolving earlier.
+    auto runNonReprocessingPass = [&](bool requireAllRecipes) -> bool
     {
-        progress = false;
-        std::set<std::string> newlyResolved;
-        for (const std::string& item : unresolved)
+        bool progress = false;
+        std::map<std::string, double> newValues;
+
+        for (std::map<std::string, std::vector<std::pair<const RecipeDef*, int>>>::const_iterator
+                 it = eligibleRecipes.begin();
+             it != eligibleRecipes.end();
+             ++it)
         {
-            std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
-                nonReprocessingRecipes.find(item);
-            if (it == nonReprocessingRecipes.end())
+            const std::string& item = it->first;
+            if (resolved.find(item) != resolved.end())
             {
                 continue;
             }
 
+            const std::vector<std::pair<const RecipeDef*, int>>& pairs = it->second;
+
+            bool allComputable = true;
             double maxThreat = -1.0;
-            for (const RecipeRef& ref : it->second)
+            for (const std::pair<const RecipeDef*, int>& pair : pairs)
             {
-                if (allInputsResolved(*ref.recipe, table.itemThreat))
+                if (!allInputsResolved(*pair.first, resolved))
                 {
-                    double threat = computeRecipeThreat(*ref.recipe, table.itemThreat);
-                    if (threat > maxThreat)
+                    allComputable = false;
+                    if (requireAllRecipes)
                     {
-                        maxThreat = threat;
+                        break;
                     }
+                    // In fallback mode: skip this recipe but continue gathering
+                    // the computable subset.
+                    continue;
+                }
+                double threat = computeRecipeThreatPerUnit(*pair.first, pair.second, resolved);
+                if (threat > maxThreat)
+                {
+                    maxThreat = threat;
                 }
             }
 
+            if (requireAllRecipes && !allComputable)
+            {
+                continue;
+            }
             if (maxThreat >= 0.0)
             {
-                table.itemThreat[item] = maxThreat;
-                newlyResolved.insert(item);
-                progress = true;
+                newValues[item] = maxThreat;
             }
         }
-        for (const std::string& item : newlyResolved)
-        {
-            unresolved.erase(item);
-        }
-    }
 
-    // Resolve reprocessing-only items.
-    for (const std::string& item : unresolved)
+        for (std::map<std::string, double>::const_iterator it = newValues.begin();
+             it != newValues.end();
+             ++it)
+        {
+            resolved[it->first] = it->second;
+            progress = true;
+        }
+        return progress;
+    };
+
+    // Reprocessing pass: resolve items produced exclusively by reprocessing.
+    // Items that also have a non-reprocessing recipe are skipped here (they are
+    // covered by the non-reprocessing pass or do not need the reprocessing path).
+    auto runReprocessingPass = [&]() -> bool
     {
-        std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
-            reprocessingRecipes.find(item);
-        if (it == reprocessingRecipes.end())
+        bool progress = false;
+        for (std::map<std::string, std::vector<RecipeRef>>::const_iterator it =
+                 reprocessingRecipes.begin();
+             it != reprocessingRecipes.end();
+             ++it)
         {
-            continue;
-        }
-
-        for (const RecipeRef& ref : it->second)
-        {
-            int scrapPerCycle = 0;
-            for (const RecipeIngredient& input : ref.recipe->inputs)
+            const std::string& item = it->first;
+            if (resolved.find(item) != resolved.end())
             {
-                scrapPerCycle += input.amount;
+                continue;
+            }
+            // Reprocessing defines an item's threat only when nothing else
+            // produces it (REQ-THREAT-ITEM).
+            if (scrapFreeItems.find(item) != scrapFreeItems.end())
+            {
+                continue;
+            }
+            // Also skip items covered by eligible (non-reprocessing) recipes.
+            if (eligibleRecipes.find(item) != eligibleRecipes.end())
+            {
+                continue;
             }
 
-            double threat = (table.scrapThreat * scrapPerCycle
-                             + ref.recipe->durationSeconds) / ref.probability;
-            std::map<std::string, double>::iterator existing = table.itemThreat.find(item);
-            if (existing == table.itemThreat.end() || threat > existing->second)
+            for (const RecipeRef& ref : it->second)
             {
-                table.itemThreat[item] = threat;
+                // Sum all scrap inputs for this reprocessing recipe.
+                int scrapPerCycle = 0;
+                for (const RecipeIngredient& input : ref.recipe->inputs)
+                {
+                    scrapPerCycle += input.amount;
+                }
+
+                double threat = (table.scrapThreat * scrapPerCycle
+                                 + ref.recipe->durationSeconds) / ref.probability;
+
+                std::map<std::string, double>::iterator existing = resolved.find(item);
+                if (existing == resolved.end() || threat > existing->second)
+                {
+                    resolved[item] = threat;
+                    progress = true;
+                }
             }
         }
+        return progress;
+    };
+
+    // Main fixpoint loop: alternate non-reprocessing and reprocessing passes
+    // until neither makes any progress (fix 8).
+    bool anyProgress = true;
+    while (anyProgress)
+    {
+        anyProgress = runNonReprocessingPass(true);
+        anyProgress = runReprocessingPass() || anyProgress;
     }
 
+    // Deadlock fallback: if any items remain unresolved due to recipe cycles,
+    // fall back to committing with the max over the currently computable subset
+    // of recipes (fix 9, deadlock guard — same approach as threat_report.py's
+    // require_all_recipes=False mode).
+    anyProgress = true;
+    while (anyProgress)
+    {
+        anyProgress = runNonReprocessingPass(false);
+        anyProgress = runReprocessingPass() || anyProgress;
+    }
+
+    // Remove the sentinel scrap entry — scrapThreat is already stored on the
+    // table struct; having it in itemThreat would confuse callers iterating items.
+    resolved.erase("scrap");
+
     return table;
 }
 

src/test/BehaviorSystemTest.cpp

@@ -984,6 +984,45 @@ TEST_CASE("BehaviorSystem: full-cargo salvage ship moves toward SalvageBay", "[b
     REQUIRE(i.target.x() < pos(f.admin, ship).value.x());
 }
 
+TEST_CASE("SalvagerSystem: full-cargo ship at its SalvageBay hands over cargo", "[behavior]")
+{
+    Fixture f;
+
+    const BuildingId bayId = f.buildings.place(BuildingType::SalvageBay,
+                                              QPoint(-4, 0), Rotation::East, 0);
+    Tick t = 0;
+    for (int i = 0; i < 500; ++i)
+    {
+        f.buildings.tickConstruction(t++);
+        if (f.buildings.findBuilding(bayId) != nullptr) { break; }
+    }
+    const Building* bay = f.buildings.findBuilding(bayId);
+    REQUIRE(bay != nullptr);
+    // Config-driven output-buffer capacity is applied on placement (REQ-BLD-SALVAGE-BAY).
+    REQUIRE(bay->outputBuffer.capacity == 20);
+
+    const QVector2D bayCenter(bay->anchor.x() + bay->footprint.width()  / 2.0f,
+                              bay->anchor.y() + bay->footprint.height() / 2.0f);
+
+    const ShipLayoutConfig salvageLayout = makeSingleModuleLayout("salvager");
+    const entt::entity ship = f.ships.spawn("salvage_ship", bayCenter, false, salvageLayout);
+    f.admin.get<PositionComponent>(ship).value = bayCenter;
+    CargoComponent& cargo = f.admin.get<CargoComponent>(ship);
+    cargo.current = cargo.maxCapacity;  // full cargo
+    const int before = cargo.current;
+    REQUIRE(before > 0);
+    f.admin.get<DeliverScrapBehavior>(ship).deliveryBay = bayId;
+
+    f.salvageTick();
+
+    // One unit handed over from cargo into the bay's output buffer.
+    REQUIRE(f.admin.get<CargoComponent>(ship).current == before - 1);
+    const Building* bayAfter = f.buildings.findBuilding(bayId);
+    REQUIRE(bayAfter != nullptr);
+    REQUIRE(bayAfter->outputBuffer.items.size() == 1);
+    REQUIRE(bayAfter->outputBuffer.items.front().type.id == "scrap");
+}
+
 // ---------------------------------------------------------------------------
 // Collection range (per-module)
 // ---------------------------------------------------------------------------

src/test/BeltSystemTest.cpp

@@ -44,14 +44,14 @@ TEST_CASE("BeltSystem: tryPutItem succeeds on registered belt", "[belt]")
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
 
-    REQUIRE(bs.tryPutItem(tile, makeItem("iron_ore")));
+    REQUIRE(bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East));
 }
 
 TEST_CASE("BeltSystem: tryPutItem fails on unregistered tile", "[belt]")
 {
     BeltSystem bs(kFastBeltSpeed);
 
-    REQUIRE_FALSE(bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore")));
+    REQUIRE_FALSE(bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East));
 }
 
 TEST_CASE("BeltSystem: tryPutItem fails after removeTile", "[belt]")
@@ -61,7 +61,7 @@ TEST_CASE("BeltSystem: tryPutItem fails after removeTile", "[belt]")
     bs.placeBelt(tile, Rotation::East);
     bs.removeTile(tile);
 
-    REQUIRE_FALSE(bs.tryPutItem(tile, makeItem("iron_ore")));
+    REQUIRE_FALSE(bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East));
 }
 
 // ---------------------------------------------------------------------------
@@ -74,10 +74,10 @@ TEST_CASE("BeltSystem: four items fit in one tile", "[belt]")
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
 
-    REQUIRE(bs.tryPutItem(tile, makeItem("a")));
-    REQUIRE(bs.tryPutItem(tile, makeItem("b")));
-    REQUIRE(bs.tryPutItem(tile, makeItem("c")));
-    REQUIRE(bs.tryPutItem(tile, makeItem("d")));
+    REQUIRE(bs.tryPutItem(tile, makeItem("a"), Rotation::East));
+    REQUIRE(bs.tryPutItem(tile, makeItem("b"), Rotation::East));
+    REQUIRE(bs.tryPutItem(tile, makeItem("c"), Rotation::East));
+    REQUIRE(bs.tryPutItem(tile, makeItem("d"), Rotation::East));
 }
 
 TEST_CASE("BeltSystem: fifth tryPutItem on full tile returns false", "[belt]")
@@ -86,12 +86,12 @@ TEST_CASE("BeltSystem: fifth tryPutItem on full tile returns false", "[belt]")
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
 
-    bs.tryPutItem(tile, makeItem("a"));
-    bs.tryPutItem(tile, makeItem("b"));
-    bs.tryPutItem(tile, makeItem("c"));
-    bs.tryPutItem(tile, makeItem("d"));
+    bs.tryPutItem(tile, makeItem("a"), Rotation::East);
+    bs.tryPutItem(tile, makeItem("b"), Rotation::East);
+    bs.tryPutItem(tile, makeItem("c"), Rotation::East);
+    bs.tryPutItem(tile, makeItem("d"), Rotation::East);
 
-    REQUIRE_FALSE(bs.tryPutItem(tile, makeItem("e")));
+    REQUIRE_FALSE(bs.tryPutItem(tile, makeItem("e"), Rotation::East));
 }
 
 // ---------------------------------------------------------------------------
@@ -103,7 +103,7 @@ TEST_CASE("BeltSystem: tryTakeItem returns placed item after reaching output edg
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("iron_ore"));
+    bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East);
     bs.tick();  // advance to output edge
 
     const std::optional<Item> taken = bs.tryTakeItem(eastPort(tile));
@@ -117,7 +117,7 @@ TEST_CASE("BeltSystem: tryTakeItem requires item to reach output edge before yie
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("iron_ore"));
+    bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East);
 
     // Item placed but not yet at output edge — must not be available.
     REQUIRE_FALSE(bs.tryTakeItem(eastPort(tile)).has_value());
@@ -133,8 +133,8 @@ TEST_CASE("BeltSystem: tryTakeItem with two items returns both after each reache
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("first"));
-    bs.tryPutItem(tile, makeItem("second"));
+    bs.tryPutItem(tile, makeItem("first"), Rotation::East);
+    bs.tryPutItem(tile, makeItem("second"), Rotation::East);
 
     // Front item reaches output edge after one tick.
     bs.tick();
@@ -169,7 +169,7 @@ TEST_CASE("BeltSystem: item transfers from tile A to tile B and becomes availabl
     bs.placeBelt(tileA, Rotation::East);
     bs.placeBelt(tileB, Rotation::East);
 
-    bs.tryPutItem(tileA, makeItem("iron_ore"));
+    bs.tryPutItem(tileA, makeItem("iron_ore"), Rotation::East);
     bs.tick();  // item reaches output edge of A, moves to B at progress 0
     bs.tick();  // item reaches output edge of B
 
@@ -185,7 +185,7 @@ TEST_CASE("BeltSystem: item stays at progress 1.0 when next tile is absent", "[b
     const QPoint tileA(0, 0);
     bs.placeBelt(tileA, Rotation::East);
 
-    bs.tryPutItem(tileA, makeItem("iron_ore"));
+    bs.tryPutItem(tileA, makeItem("iron_ore"), Rotation::East);
     bs.tick();
 
     // Item should still be on tileA (no registered tile to the east).
@@ -202,7 +202,7 @@ TEST_CASE("BeltSystem: item traverses 3-tile chain in 3 ticks (one per tile)", "
     bs.placeBelt(tileB, Rotation::East);
     bs.placeBelt(tileC, Rotation::East);
 
-    bs.tryPutItem(tileA, makeItem("iron_ore"));
+    bs.tryPutItem(tileA, makeItem("iron_ore"), Rotation::East);
     bs.tick();  // A output edge → moves to B at progress 0
     bs.tick();  // B output edge → moves to C at progress 0
     bs.tick();  // C output edge → available for pickup
@@ -221,13 +221,13 @@ TEST_CASE("BeltSystem: item stays blocked when next tile is full", "[belt]")
     bs.placeBelt(tileB, Rotation::East);
 
     // Fill tileB to capacity.
-    bs.tryPutItem(tileB, makeItem("b1"));
-    bs.tryPutItem(tileB, makeItem("b2"));
-    bs.tryPutItem(tileB, makeItem("b3"));
-    bs.tryPutItem(tileB, makeItem("b4"));
+    bs.tryPutItem(tileB, makeItem("b1"), Rotation::East);
+    bs.tryPutItem(tileB, makeItem("b2"), Rotation::East);
+    bs.tryPutItem(tileB, makeItem("b3"), Rotation::East);
+    bs.tryPutItem(tileB, makeItem("b4"), Rotation::East);
 
     // Place item in tileA — should be blocked.
-    bs.tryPutItem(tileA, makeItem("a1"));
+    bs.tryPutItem(tileA, makeItem("a1"), Rotation::East);
     bs.tick();
 
     // Item in tileA must still be there.
@@ -246,13 +246,13 @@ TEST_CASE("BeltSystem: belt second slot is capped at progress 0.75", "[belt]")
     bs.placeBelt(tile, Rotation::East);
 
     // Advance front item to the output edge; it stays there (no next tile).
-    bs.tryPutItem(tile, makeItem("front_item"));
+    bs.tryPutItem(tile, makeItem("front_item"), Rotation::East);
     bs.tick();  // slot[0]: 0.4
     bs.tick();  // slot[0]: 0.8
     bs.tick();  // slot[0]: 1.0 (capped, stuck)
 
     // Place second item; slot[0] is at 1.0.
-    bs.tryPutItem(tile, makeItem("back_item"));
+    bs.tryPutItem(tile, makeItem("back_item"), Rotation::East);
     bs.tick();  // slot[1]: 0.4
     bs.tick();  // slot[1] would reach 0.8 — capped at 0.75
 
@@ -272,8 +272,8 @@ TEST_CASE("BeltSystem: clearTiles removes all items from specified tiles", "[bel
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("iron_ore"));
-    bs.tryPutItem(tile, makeItem("copper_ore"));
+    bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East);
+    bs.tryPutItem(tile, makeItem("copper_ore"), Rotation::East);
 
     bs.clearTiles({tile});
 
@@ -289,7 +289,7 @@ TEST_CASE("BeltSystem: forEachVisualItem visits items inside viewport", "[belt]"
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(5, 5);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("iron_ore"));
+    bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East);
 
     int count = 0;
     bs.forEachVisualItem(QRect(0, 0, 20, 20), [&count](VisualItem) { ++count; });
@@ -302,7 +302,7 @@ TEST_CASE("BeltSystem: forEachVisualItem skips items outside viewport", "[belt]"
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(50, 50);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("iron_ore"));
+    bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East);
 
     int count = 0;
     bs.forEachVisualItem(QRect(0, 0, 20, 20), [&count](VisualItem) { ++count; });
@@ -315,7 +315,7 @@ TEST_CASE("BeltSystem: forEachVisualItem reports correct ItemType", "[belt]")
     BeltSystem bs(kFastBeltSpeed);
     const QPoint tile(0, 0);
     bs.placeBelt(tile, Rotation::East);
-    bs.tryPutItem(tile, makeItem("copper_ingot"));
+    bs.tryPutItem(tile, makeItem("copper_ingot"), Rotation::East);
 
     std::vector<ItemType> seen;
     bs.forEachVisualItem(QRect(-1, -1, 10, 10), [&seen](VisualItem vi)
@@ -348,10 +348,10 @@ TEST_CASE("BeltSystem: splitter alternates between outputA and outputB", "[belt]
     bs.placeBelt(tileA, Rotation::North);
     bs.placeBelt(tileB, Rotation::South);
 
-    bs.tryPutItem(tileIn, makeItem("item1"));
+    bs.tryPutItem(tileIn, makeItem("item1"), Rotation::East);
     bs.tick();   // item1: tileIn -> splitter back (progress 0)
 
-    bs.tryPutItem(tileIn, makeItem("item2"));
+    bs.tryPutItem(tileIn, makeItem("item2"), Rotation::East);
     bs.tick();   // item1 back -> 0.5 -> frontA; item2 advances but back is occupied
     bs.tick();   // item1 frontA -> 1.0 -> tileA; item2 enters splitter back
     bs.tick();   // item2 back -> 0.5 -> frontB; item1 at tileA output edge
@@ -388,7 +388,7 @@ TEST_CASE("BeltSystem: splitter routes to preferred output when item matches bot
 
     bs.setSplitterFilters(tileSpl, {ItemType{"iron_ore"}}, {});
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();   // tileIn -> splitter back
     bs.tick();   // back -> frontA (both match, alternation, preferred A)
     bs.tick();   // frontA -> tileA
@@ -411,7 +411,7 @@ TEST_CASE("BeltSystem: splitter routes item to output A when only filter A match
 
     bs.setSplitterFilters(tileSpl, {ItemType{"iron_ore"}}, {ItemType{"copper_ore"}});
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();   // tileIn -> splitter back
     bs.tick();   // back -> frontA (exclusive match to A)
     bs.tick();   // frontA reaches 1.0; no downstream belt, waits for building pickup
@@ -433,7 +433,7 @@ TEST_CASE("BeltSystem: splitter routes item to output B when only filter B match
 
     bs.setSplitterFilters(tileSpl, {ItemType{"copper_ore"}}, {ItemType{"iron_ore"}});
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();
@@ -456,17 +456,17 @@ TEST_CASE("BeltSystem: splitter alternates A then B when item matches both expli
     bs.setSplitterFilters(tileSpl, {ItemType{"iron_ore"}}, {ItemType{"iron_ore"}});
 
     // Item 1 → preferred A (nextOutputIsA=true initially).
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::North}).has_value());
 
     // Item 2 → preferred B (nextOutputIsA toggled to false).
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::South}).has_value());
 
     // Item 3 → preferred A again (nextOutputIsA toggled back to true).
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();
     REQUIRE(bs.peekItem(Port{tileSpl, Rotation::North}).has_value());
     REQUIRE_FALSE(bs.peekItem(Port{tileSpl, Rotation::South}).has_value());
@@ -486,7 +486,7 @@ TEST_CASE("BeltSystem: splitter routes unmatched item to the unfiltered output",
 
     bs.setSplitterFilters(tileSpl, {ItemType{"copper_ore"}}, {});
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();
 
     REQUIRE_FALSE(bs.peekItem(Port{tileSpl, Rotation::North}).has_value());
@@ -506,7 +506,7 @@ TEST_CASE("BeltSystem: splitter stalls when item matches neither filter", "[belt
 
     bs.setSplitterFilters(tileSpl, {ItemType{"copper_ore"}}, {ItemType{"iron_ingot"}});
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();   // tileIn -> splitter back
     bs.tick();   // back reaches 0.5; routing fires but stalls (no filter match)
     bs.tick();   // back stays at 0.5; stall persists
@@ -530,17 +530,17 @@ TEST_CASE("BeltSystem: splitter falls back to other output when preferred is blo
     bs.setSplitterFilters(tileSpl, {ItemType{"iron_ore"}}, {ItemType{"iron_ore"}});
 
     // Item 1 → preferred A (nextOutputIsA=true → false after routing).
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();   // frontA = item1 at 1.0
 
     // Item 2 → preferred B (nextOutputIsA=false → true after routing). Take item2 to free frontB.
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();   // frontB = item2 at 1.0
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::South}).has_value());
 
     // frontA still holds item1; nextOutputIsA=true (prefer A).
     // Item 3: both match, preferred A is occupied → fallback to B without toggling nextOutputIsA.
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();   // frontB = item3 at 1.0
 
     REQUIRE(bs.peekItem(Port{tileSpl, Rotation::North}).has_value());  // item1 still in A
@@ -549,7 +549,7 @@ TEST_CASE("BeltSystem: splitter falls back to other output when preferred is blo
     // nextOutputIsA was not toggled by the fallback: next item should still prefer A.
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::North}).has_value());  // free frontA
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::South}).has_value());  // free frontB
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick(); bs.tick(); bs.tick();
     REQUIRE(bs.peekItem(Port{tileSpl, Rotation::North}).has_value());  // item4 → A (preferA still true)
     REQUIRE_FALSE(bs.peekItem(Port{tileSpl, Rotation::South}).has_value());
@@ -591,14 +591,14 @@ TEST_CASE("BeltSystem: splitter fallback enters the open output at progress 0.75
 
     // Permanently block output A: route one item to frontA where it sticks at 1.0
     // (North has no downstream tile, so it can never move out).
-    bs.tryPutItem(tileSpl, makeItem("blockA"));
+    bs.tryPutItem(tileSpl, makeItem("blockA"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> frontA at 0.75 (preferred A), nextOutputIsA = false
     bs.tick(); bs.tick();  // frontA: 0.75 -> 1.0 (stuck, no North downstream)
 
     // Cycle one item through B as the *preferred* output (also enters at 0.75) to
     // flip nextOutputIsA back to true and free frontB for the fallback case below.
-    bs.tryPutItem(tileSpl, makeItem("toB_pref"));
+    bs.tryPutItem(tileSpl, makeItem("toB_pref"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> frontB at 0.75 (preferred B), nextOutputIsA = true
     REQUIRE(southProgressOf("toB_pref") == Approx(0.75));
@@ -608,7 +608,7 @@ TEST_CASE("BeltSystem: splitter fallback enters the open output at progress 0.75
 
     // Next item prefers A again (nextOutputIsA == true), but A is still blocked,
     // so it falls back to B — and must enter near the edge at progress 0.75.
-    bs.tryPutItem(tileSpl, makeItem("toB_fallback"));
+    bs.tryPutItem(tileSpl, makeItem("toB_fallback"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> fallback routes to frontB at 0.75
     REQUIRE(southProgressOf("toB_fallback") == Approx(0.75));
@@ -648,13 +648,13 @@ TEST_CASE("BeltSystem: splitter with an exclusive filter enters its only output
     };
 
     // iron_ore matches filterA only -> sole eligible output A.
-    bs.tryPutItem(tileSpl, makeItem("iron_ore"));
+    bs.tryPutItem(tileSpl, makeItem("iron_ore"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> routes to frontA at 0.75
     REQUIRE(progressOf("iron_ore", Rotation::North) == Approx(0.75));
 
     // copper_ore matches filterB only -> sole eligible output B.
-    bs.tryPutItem(tileSpl, makeItem("copper_ore"));
+    bs.tryPutItem(tileSpl, makeItem("copper_ore"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> routes to frontB at 0.75
     REQUIRE(progressOf("copper_ore", Rotation::South) == Approx(0.75));
@@ -692,13 +692,13 @@ TEST_CASE("BeltSystem: splitter alternation enters the preferred output at progr
     };
 
     // First item: preferred A (nextOutputIsA starts true) -> frontA at 0.75.
-    bs.tryPutItem(tileSpl, makeItem("first"));
+    bs.tryPutItem(tileSpl, makeItem("first"), Rotation::East);
     bs.tick();  // back: 0.25
     bs.tick();  // back: 0.5 -> routes to preferred frontA at 0.75, nextOutputIsA = false
     REQUIRE(progressOf("first", Rotation::North) == Approx(0.75));
 
     // Second item: preference flipped, B is free -> frontB at 0.75.
-    bs.tryPutItem(tileSpl, makeItem("second"));
+    bs.tryPutItem(tileSpl, makeItem("second"), Rotation::East);
     bs.tick();  // back: 0.25 (first sticks at North 1.0, no downstream)
     bs.tick();  // back: 0.5 -> routes to preferred frontB at 0.75
     REQUIRE(progressOf("second", Rotation::South) == Approx(0.75));
@@ -718,7 +718,7 @@ TEST_CASE("BeltSystem: splitter back slot is capped at 0.5 and waits before rout
     bs.placeBelt(tileIn, Rotation::East);
     bs.placeSplitter(tileSpl, Rotation::North, Rotation::South);
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();   // item enters splitter back at progress 0; routing not yet triggered
 
     // Back has not yet reached 0.5 — front slots empty, nothing available.
@@ -743,7 +743,7 @@ TEST_CASE("BeltSystem: splitter delivers item directly to building input via try
     bs.placeSplitter(tileSpl, Rotation::North, Rotation::South);
     // No output belts — both outputs lead directly to building inputs.
 
-    bs.tryPutItem(tileIn, makeItem("iron_ore"));
+    bs.tryPutItem(tileIn, makeItem("iron_ore"), Rotation::East);
     bs.tick();   // tileIn -> splitter back
     bs.tick();   // back -> frontA at progress 0
     bs.tick();   // frontA reaches 1.0; no downstream belt, item waits for building pickup
@@ -766,7 +766,7 @@ TEST_CASE("BeltSystem: splitter accepts new items after building pulls from fron
     bs.placeBelt(tileIn, Rotation::East);
     bs.placeSplitter(tileSpl, Rotation::North, Rotation::South);
 
-    bs.tryPutItem(tileIn, makeItem("item1"));
+    bs.tryPutItem(tileIn, makeItem("item1"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();   // item1 now in frontA at 1.0
@@ -775,7 +775,7 @@ TEST_CASE("BeltSystem: splitter accepts new items after building pulls from fron
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::North}).has_value());
 
     // Feed item2; preferred is now South.
-    bs.tryPutItem(tileIn, makeItem("item2"));
+    bs.tryPutItem(tileIn, makeItem("item2"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();   // item2 now in frontB at 1.0
@@ -812,21 +812,21 @@ TEST_CASE("BeltSystem: splitter alternates between two unregistered outputs (bui
     bs.placeSplitter(tileSpl, Rotation::North, Rotation::South);
 
     // item1 → frontA (preferred, nextOutputIsA=true)
-    bs.tryPutItem(tileIn, makeItem("item1"));
+    bs.tryPutItem(tileIn, makeItem("item1"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::North}).has_value());
 
     // item2 → frontB (preferred, nextOutputIsA now false)
-    bs.tryPutItem(tileIn, makeItem("item2"));
+    bs.tryPutItem(tileIn, makeItem("item2"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();
     REQUIRE(bs.tryTakeItem(Port{tileSpl, Rotation::South}).has_value());
 
     // item3 → frontA again (nextOutputIsA toggled back to true)
-    bs.tryPutItem(tileIn, makeItem("item3"));
+    bs.tryPutItem(tileIn, makeItem("item3"), Rotation::East);
     bs.tick();
     bs.tick();
     bs.tick();
@@ -847,7 +847,7 @@ TEST_CASE("BeltSystem: tunnel pairing — basic pair within max distance", "[bel
     bs.placeTunnelEntry(entry, Rotation::East, 10);
     bs.placeTunnelExit(exit, Rotation::East);
 
-    bs.tryPutItem(entry, makeItem("iron_ore"));
+    bs.tryPutItem(entry, makeItem("iron_ore"), Rotation::East);
 
     // With kFastBeltSpeed, items cross one tile per tick.
     // entry tile: 1 tick to reach front progress 1.0
@@ -873,7 +873,7 @@ TEST_CASE("BeltSystem: tunnel pairing — wrong direction prevents pair", "[belt
     bs.placeTunnelEntry(QPoint(0, 0), Rotation::East, 10);
     bs.placeTunnelExit(QPoint(3, 0), Rotation::North);
 
-    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"));
+    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East);
 
     for (int i = 0; i < 20; ++i)
     {
@@ -891,7 +891,7 @@ TEST_CASE("BeltSystem: tunnel pairing — beyond max distance prevents pair", "[
     bs.placeTunnelEntry(QPoint(0, 0), Rotation::East, 2);
     bs.placeTunnelExit(QPoint(3, 0), Rotation::East);
 
-    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"));
+    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East);
 
     for (int i = 0; i < 20; ++i)
     {
@@ -912,7 +912,7 @@ TEST_CASE("BeltSystem: tunnel pairing — same-dir entry between blocks pairing"
     bs.placeTunnelExit(QPoint(4, 0), Rotation::East);
 
     // Put item on Entry2 — should reach exit.
-    bs.tryPutItem(QPoint(2, 0), makeItem("copper_ore"));
+    bs.tryPutItem(QPoint(2, 0), makeItem("copper_ore"), Rotation::East);
     for (int i = 0; i < 20; ++i)
     {
         bs.tick();
@@ -921,7 +921,7 @@ TEST_CASE("BeltSystem: tunnel pairing — same-dir entry between blocks pairing"
     bs.tryTakeItem(Port{QPoint(4, 0), Rotation::East});
 
     // Put item on Entry1 — should NOT reach exit (Entry1 is unpaired).
-    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"));
+    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East);
     for (int i = 0; i < 20; ++i)
     {
         bs.tick();
@@ -939,7 +939,7 @@ TEST_CASE("BeltSystem: tunnel pairing — cross-dir entry between is ignored", "
     bs.placeTunnelEntry(QPoint(2, 0), Rotation::North, 10);
     bs.placeTunnelExit(QPoint(4, 0), Rotation::East);
 
-    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"));
+    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East);
     for (int i = 0; i < 20; ++i)
     {
         bs.tick();
@@ -958,7 +958,7 @@ TEST_CASE("BeltSystem: unpaired entry blocks items at front", "[belt]")
     bs.placeTunnelEntry(QPoint(0, 0), Rotation::East, 10);
     // No exit placed — entry is unpaired.
 
-    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"));
+    bs.tryPutItem(QPoint(0, 0), makeItem("iron_ore"), Rotation::East);
     for (int i = 0; i < 10; ++i)
     {
         bs.tick();
@@ -984,7 +984,7 @@ TEST_CASE("BeltSystem: demolish entry discards transit items", "[belt]")
     bs.placeTunnelEntry(entry, Rotation::East, 10);
     bs.placeTunnelExit(exit, Rotation::East);
 
-    bs.tryPutItem(entry, makeItem("iron_ore"));
+    bs.tryPutItem(entry, makeItem("iron_ore"), Rotation::East);
 
     // Advance just enough for item to enter transit but not reach exit.
     bs.tick();  // item enters entry front
@@ -1010,7 +1010,7 @@ TEST_CASE("BeltSystem: clearTiles discards tunnel transit items", "[belt]")
     bs.placeTunnelEntry(entry, Rotation::East, 10);
     bs.placeTunnelExit(exit, Rotation::East);
 
-    bs.tryPutItem(entry, makeItem("iron_ore"));
+    bs.tryPutItem(entry, makeItem("iron_ore"), Rotation::East);
     bs.tick();
     bs.tick();
 
@@ -1037,7 +1037,7 @@ TEST_CASE("BeltSystem: belt to entry to transit to exit to belt full chain", "[b
     bs.placeTunnelExit(exit, Rotation::East);
     bs.placeBelt(beltOut, Rotation::East);
 
-    bs.tryPutItem(beltIn, makeItem("iron_ore"));
+    bs.tryPutItem(beltIn, makeItem("iron_ore"), Rotation::East);
 
     for (int i = 0; i < 30; ++i)
     {
@@ -1061,11 +1061,11 @@ TEST_CASE("BeltSystem: multiple items transit tunnel in order", "[belt]")
     bs.placeTunnelEntry(entry, Rotation::East, 10);
     bs.placeTunnelExit(exit, Rotation::East);
 
-    bs.tryPutItem(entry, makeItem("item1"));
+    bs.tryPutItem(entry, makeItem("item1"), Rotation::East);
     bs.tick();
     bs.tick();  // item1 enters transit
 
-    bs.tryPutItem(entry, makeItem("item2"));
+    bs.tryPutItem(entry, makeItem("item2"), Rotation::East);
 
     for (int i = 0; i < 30; ++i)
     {
@@ -1086,3 +1086,94 @@ TEST_CASE("BeltSystem: multiple items transit tunnel in order", "[belt]")
     REQUIRE(taken2.has_value());
     REQUIRE(taken2->type.id == "item2");
 }
+
+// ---------------------------------------------------------------------------
+// Output-edge rejection (REQ-MAT-ACCEPT-DIR)
+// ---------------------------------------------------------------------------
+
+TEST_CASE("BeltSystem: belt refuses an item arriving through its output edge", "[belt]")
+{
+    // Belt A flows East into belt B, but B flows West — so the hand-off would
+    // enter B through its own (West) output edge and must be refused. Without the
+    // guard the item would ping-pong between the two belts forever.
+    BeltSystem bs(kFastBeltSpeed);
+    const QPoint tileA(0, 0);
+    const QPoint tileB(1, 0);
+    bs.placeBelt(tileA, Rotation::East);
+    bs.placeBelt(tileB, Rotation::West);
+
+    REQUIRE(bs.tryPutItem(tileA, makeItem("iron_ore"), Rotation::East));
+    for (int i = 0; i < 5; ++i)
+    {
+        bs.tick();
+    }
+
+    // B never accepts the item through its output edge...
+    REQUIRE_FALSE(bs.tryTakeItem(Port{tileB, Rotation::West}).has_value());
+    // ...and it stays blocked at A's output edge.
+    REQUIRE(bs.tryTakeItem(eastPort(tileA)).has_value());
+}
+
+TEST_CASE("BeltSystem: tryPutItem refuses a deposit onto a belt facing the source", "[belt]")
+{
+    // A belt whose output edge faces back toward the depositing building must
+    // refuse the item; feeding through a non-output edge still works.
+    BeltSystem bs(kFastBeltSpeed);
+    const QPoint tile(0, 0);
+    bs.placeBelt(tile, Rotation::West);
+
+    // Item travelling East enters through the West (output) edge -> refused.
+    REQUIRE_FALSE(bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::East));
+    // Item travelling West enters through the East (back) edge -> accepted.
+    REQUIRE(bs.tryPutItem(tile, makeItem("iron_ore"), Rotation::West));
+}
+
+TEST_CASE("BeltSystem: splitter refuses an item arriving through an output edge", "[belt]")
+{
+    BeltSystem bs(kFastBeltSpeed);
+    const QPoint tileSpl(1, 0);
+    bs.placeSplitter(tileSpl, Rotation::North, Rotation::South);
+
+    // Entering through the North output edge (item travelling South) -> refused.
+    REQUIRE_FALSE(bs.tryPutItem(tileSpl, makeItem("iron_ore"), Rotation::South));
+    // Entering through the South output edge (item travelling North) -> refused.
+    REQUIRE_FALSE(bs.tryPutItem(tileSpl, makeItem("iron_ore"), Rotation::North));
+    // Entering through a non-output (West) edge (item travelling East) -> accepted.
+    REQUIRE(bs.tryPutItem(tileSpl, makeItem("iron_ore"), Rotation::East));
+}
+
+TEST_CASE("BeltSystem: tunnel entry refuses an item arriving through its mouth edge", "[belt]")
+{
+    BeltSystem bs(kFastBeltSpeed);
+    const QPoint entry(0, 0);
+    bs.placeTunnelEntry(entry, Rotation::East, 10);
+
+    // Item travelling West enters through the East mouth (output) edge -> refused.
+    REQUIRE_FALSE(bs.tryPutItem(entry, makeItem("iron_ore"), Rotation::West));
+    // Item travelling East enters through the back (West) edge -> accepted.
+    REQUIRE(bs.tryPutItem(entry, makeItem("iron_ore"), Rotation::East));
+}
+
+TEST_CASE("BeltSystem: tunnel exit refuses an item pushed into its output edge", "[belt]")
+{
+    // A splitter's East front sits next to a tunnel exit whose output faces West
+    // (back toward the splitter). The front cannot hand off into the exit's
+    // output edge, so the item stays on the splitter front.
+    BeltSystem bs(kFastBeltSpeed);
+    const QPoint tileSpl(1, 0);
+    const QPoint exitTile(2, 0);
+    bs.placeSplitter(tileSpl, Rotation::East, Rotation::South);
+    bs.placeTunnelExit(exitTile, Rotation::West);
+
+    // Feed through the West edge (item travelling East); first item routes to the
+    // East front (nextOutputIsA starts true).
+    REQUIRE(bs.tryPutItem(tileSpl, makeItem("iron_ore"), Rotation::East));
+    for (int i = 0; i < 5; ++i)
+    {
+        bs.tick();
+    }
+
+    // The item is stuck on the splitter's East front; the exit never received it.
+    REQUIRE(bs.peekItem(Port{tileSpl, Rotation::East}).has_value());
+    REQUIRE_FALSE(bs.peekItem(Port{exitTile, Rotation::West}).has_value());
+}

src/test/BlueprintTest.cpp

@@ -8,6 +8,7 @@
 
 #include "Blueprint.h"
 #include "Building.h"
+#include "BuildingConfig.h"
 #include "BuildingsConfig.h"
 #include "BuildingSystem.h"
 #include "BuildingType.h"
@@ -696,6 +697,92 @@ TEST_CASE("Blueprint placement: recipe transfers to building after construction
     REQUIRE(b->recipeId == "mine_copper_ore");
 }
 
+// ---------------------------------------------------------------------------
+// Blueprint capture from construction sites (REQ-UI-BLUEPRINT-CREATE,
+// REQ-UI-BLUEPRINT-STORAGE): a still-under-construction building is a valid
+// blueprint source, captured identically to an operational building.
+// ---------------------------------------------------------------------------
+
+TEST_CASE("Blueprint creation: a construction site is captured", "[blueprint]")
+{
+    Simulation sim(loadConfig());
+
+    // Freshly placed → a ConstructionSite (not ticked to completion). A 1x1 belt keeps
+    // the body-cell bounding-box centered on the anchor, so a single site → zero offset.
+    const BuildingId id =
+        SimulationTestAccess::place(sim, BuildingType::Belt, QPoint(-2, 0), Rotation::East);
+    REQUIRE(id != kInvalidBuildingId);
+    REQUIRE(sim.buildings().findSite(id) != nullptr);
+    REQUIRE(sim.buildings().findBuilding(id) == nullptr);
+
+    const Blueprint bp = captureBlueprintFromSelection(sim, { id });
+
+    REQUIRE(bp.buildings.size() == 1);
+    REQUIRE(bp.buildings[0].type == BuildingType::Belt);
+    REQUIRE(bp.buildings[0].offset == QPoint(0, 0)); // single 1x1 building → zero offset
+}
+
+TEST_CASE("Blueprint creation: a construction site's recipe is captured", "[blueprint]")
+{
+    Simulation sim(loadConfig());
+
+    const BuildingId id =
+        SimulationTestAccess::place(sim, BuildingType::Miner, QPoint(-2, 0), Rotation::East);
+    REQUIRE(id != kInvalidBuildingId);
+    SimulationTestAccess::buildings(sim).setRecipe(id, "mine_iron_ore");
+
+    const Blueprint bp = captureBlueprintFromSelection(sim, { id });
+
+    REQUIRE(bp.buildings.size() == 1);
+    REQUIRE(bp.buildings[0].recipeId == "mine_iron_ore");
+}
+
+TEST_CASE("Blueprint creation: mixed operational building and construction site are both captured",
+          "[blueprint]")
+{
+    Simulation sim(loadConfig());
+
+    // Building A: place, configure, and tick to completion so it is operational.
+    const BuildingId idA =
+        SimulationTestAccess::place(sim, BuildingType::Miner, QPoint(-2, 0), Rotation::East);
+    REQUIRE(idA != kInvalidBuildingId);
+    SimulationTestAccess::buildings(sim).setRecipe(idA, "mine_iron_ore");
+    for (int i = 0; i <= static_cast<int>(secondsToTicks(10.0)); ++i) { sim.tick(); }
+    REQUIRE(sim.buildings().findBuilding(idA) != nullptr);
+
+    // Building B: place and configure, but leave as a construction site.
+    const BuildingId idB =
+        SimulationTestAccess::place(sim, BuildingType::Miner, QPoint(-6, 0), Rotation::East);
+    REQUIRE(idB != kInvalidBuildingId);
+    SimulationTestAccess::buildings(sim).setRecipe(idB, "mine_copper_ore");
+    REQUIRE(sim.buildings().findSite(idB) != nullptr);
+
+    const Blueprint bp = captureBlueprintFromSelection(sim, { idA, idB });
+
+    REQUIRE(bp.buildings.size() == 2);
+    REQUIRE(bp.buildings[0].type == BuildingType::Miner);
+    REQUIRE(bp.buildings[1].type == BuildingType::Miner);
+    // Both the operational building's and the site's configs come through.
+    std::vector<std::string> recipes = { bp.buildings[0].recipeId, bp.buildings[1].recipeId };
+    std::sort(recipes.begin(), recipes.end());
+    REQUIRE(recipes == std::vector<std::string>{ "mine_copper_ore", "mine_iron_ore" });
+    // Distinct anchors → distinct offsets.
+    REQUIRE(bp.buildings[0].offset != bp.buildings[1].offset);
+}
+
+TEST_CASE("Blueprint creation: selectionHasPlaceableBuilding sees a construction site", "[blueprint]")
+{
+    Simulation sim(loadConfig());
+
+    REQUIRE_FALSE(selectionHasPlaceableBuilding(sim, {}));
+
+    const BuildingId id =
+        SimulationTestAccess::place(sim, BuildingType::Miner, QPoint(-2, 0), Rotation::East);
+    REQUIRE(id != kInvalidBuildingId);
+    REQUIRE(sim.buildings().findSite(id) != nullptr);
+    REQUIRE(selectionHasPlaceableBuilding(sim, { id }));
+}
+
 TEST_CASE("Blueprint placement: interceptor schematic is unlocked at game start", "[blueprint]")
 {
     // "interceptor" has unlock_at_station_level = -1 in the test config.

src/test/BuildingConfigTest.cpp

@@ -0,0 +1,133 @@
+#include "catch.hpp"
+
+#include "Building.h"
+#include "BuildingConfig.h"
+#include "BuildingSystem.h"
+#include "BuildingType.h"
+#include "ConfigLoader.h"
+#include "GameConfig.h"
+#include "Rotation.h"
+#include "ShipLayout.h"
+#include "ShipsConfig.h"
+#include "Simulation.h"
+#include "SimulationTestAccess.h"
+
+// readBuildingConfig underpins the copy-settings gesture (REQ-BLD-COPY-CONFIG):
+// it extracts a building's recipe / schematic / layout / splitter filters so they
+// can be stamped onto a same-type building. It reads operational buildings and
+// construction sites alike.
+
+namespace
+{
+GameConfig loadConfig()
+{
+    return ConfigLoader::loadFromDirectory(CONFIG_DIR);
+}
+
+const BuildingDef* findDef(const GameConfig& cfg, BuildingType type)
+{
+    for (const BuildingDef& def : cfg.buildings.buildings)
+    {
+        if (def.type == type) { return &def; }
+    }
+    return nullptr;
+}
+
+BuildingId placeOperational(Simulation& sim, const GameConfig& cfg,
+                            BuildingType type, QPoint anchor)
+{
+    const BuildingDef* def = findDef(cfg, type);
+    REQUIRE(def != nullptr);
+    return SimulationTestAccess::buildings(sim).placeImmediate(
+        type, def->surfaceMask, anchor, Rotation::East);
+}
+
+const ShipDef* findAvailableSchematic(const GameConfig& cfg)
+{
+    for (const ShipDef& def : cfg.ships.ships)
+    {
+        if (def.unlockAtStationLevel == -1) { return &def; }
+    }
+    return nullptr;
+}
+}  // namespace
+
+TEST_CASE("readBuildingConfig returns a miner's selected recipe", "[copyconfig]")
+{
+    const GameConfig cfg = loadConfig();
+    Simulation sim(loadConfig(), 7);
+
+    const BuildingId id = placeOperational(sim, cfg, BuildingType::Miner, QPoint(0, 0));
+    SimulationTestAccess::buildings(sim).setRecipe(id, "mine_iron_ore");
+
+    const std::optional<BuildingConfig> config = readBuildingConfig(sim, id);
+    REQUIRE(config.has_value());
+    CHECK(config->type == BuildingType::Miner);
+    REQUIRE(config->recipeId.has_value());
+    CHECK(*config->recipeId == "mine_iron_ore");
+    CHECK_FALSE(config->isSplitter);
+    CHECK_FALSE(config->shipLayout.has_value());
+}
+
+TEST_CASE("readBuildingConfig leaves recipe unset when nothing is selected",
+          "[copyconfig]")
+{
+    const GameConfig cfg = loadConfig();
+    Simulation sim(loadConfig(), 7);
+
+    const BuildingId id = placeOperational(sim, cfg, BuildingType::Assembler, QPoint(0, 0));
+
+    const std::optional<BuildingConfig> config = readBuildingConfig(sim, id);
+    REQUIRE(config.has_value());
+    CHECK(config->type == BuildingType::Assembler);
+    CHECK_FALSE(config->recipeId.has_value());  // nothing to copy
+    CHECK_FALSE(config->isSplitter);
+}
+
+TEST_CASE("readBuildingConfig returns a shipyard's schematic and layout",
+          "[copyconfig]")
+{
+    const GameConfig cfg = loadConfig();
+    Simulation sim(loadConfig(), 7);
+
+    const ShipDef* schematic = findAvailableSchematic(cfg);
+    REQUIRE(schematic != nullptr);
+
+    const BuildingId id = placeOperational(sim, cfg, BuildingType::Shipyard, QPoint(0, 0));
+    SimulationTestAccess::buildings(sim).setRecipe(id, schematic->id);
+    SimulationTestAccess::buildings(sim).setShipLayout(id, ShipLayoutConfig{});
+
+    const std::optional<BuildingConfig> config = readBuildingConfig(sim, id);
+    REQUIRE(config.has_value());
+    CHECK(config->type == BuildingType::Shipyard);
+    REQUIRE(config->recipeId.has_value());
+    CHECK(*config->recipeId == schematic->id);
+    CHECK(config->shipLayout.has_value());
+}
+
+TEST_CASE("readBuildingConfig reads a queued construction site", "[copyconfig]")
+{
+    const GameConfig cfg = loadConfig();
+    Simulation sim(loadConfig(), 7);
+
+    // A placed miner enters the construction queue as a site (not yet operational).
+    const BuildingId id =
+        SimulationTestAccess::place(sim, BuildingType::Miner, QPoint(-2, 0), Rotation::East);
+    REQUIRE(id != kInvalidBuildingId);
+    REQUIRE(sim.buildings().findBuilding(id) == nullptr);
+    REQUIRE(sim.buildings().findSite(id) != nullptr);
+
+    SimulationTestAccess::buildings(sim).setRecipe(id, "mine_iron_ore");
+
+    const std::optional<BuildingConfig> config = readBuildingConfig(sim, id);
+    REQUIRE(config.has_value());
+    CHECK(config->type == BuildingType::Miner);
+    REQUIRE(config->recipeId.has_value());
+    CHECK(*config->recipeId == "mine_iron_ore");
+}
+
+TEST_CASE("readBuildingConfig returns nullopt for an unknown id", "[copyconfig]")
+{
+    Simulation sim(loadConfig(), 7);
+    CHECK_FALSE(readBuildingConfig(sim, kInvalidBuildingId).has_value());
+}

src/test/BuildingTest.cpp

@@ -58,12 +58,28 @@ static void runTicks(BuildingSystem& bs, BeltSystem& belts, int n, Tick& tick)
         bs.tickConstruction(tick);
         bs.tickBeltPull();
         bs.tickProduction(tick);
-        bs.tickBeltPush();
+        bs.tickOutputBelts();
         belts.tick();
         ++tick;
     }
 }
 
+// All items currently on a building's output side: buffered plus still-emerging on
+// the virtual output belts (REQ-MAT-OUTPUT-EMERGE). A produced item leaves the
+// output buffer the moment it starts emerging, so tests count both.
+static std::vector<Item> outputSideItems(const Building& b)
+{
+    std::vector<Item> items = b.outputBuffer.items;
+    for (const std::vector<BeltItemSlot>& lane : b.emergingItems)
+    {
+        for (const BeltItemSlot& slot : lane)
+        {
+            items.push_back(slot.item);
+        }
+    }
+    return items;
+}
+
 // Owns a BuildingSystem and its dependencies for placement-bounds tests.
 struct PlacementFixture
 {
@@ -214,13 +230,13 @@ TEST_CASE("BuildingSystem: placing a belt registers it with BeltSystem after con
     bs.place(BuildingType::Belt, QPoint(5, 5), Rotation::East, 0);
 
     // Belt is queued — not yet in BeltSystem.
-    REQUIRE_FALSE(belts.tryPutItem(QPoint(5, 5), makeItem("iron_ore")));
+    REQUIRE_FALSE(belts.tryPutItem(QPoint(5, 5), makeItem("iron_ore"), Rotation::East));
 
     // Complete construction (1 s).
     Tick tick = 0;
     runTicks(bs, belts, static_cast<int>(secondsToTicks(1.0)) + 1, tick);
 
-    REQUIRE(belts.tryPutItem(QPoint(5, 5), makeItem("iron_ore")));
+    REQUIRE(belts.tryPutItem(QPoint(5, 5), makeItem("iron_ore"), Rotation::East));
     REQUIRE(bs.allBuildings().size() == 1);
     REQUIRE(bs.allBuildings()[0].type == BuildingType::Belt);
     REQUIRE(bs.allBuildings()[0].anchor == QPoint(5, 5));
@@ -402,8 +418,11 @@ TEST_CASE("BuildingSystem: miner produces iron_ore after recipe duration", "[bui
 
     const Building* b = bs.findBuilding(id);
     REQUIRE(b != nullptr);
-    REQUIRE_FALSE(b->outputBuffer.items.empty());
-    REQUIRE(b->outputBuffer.items.front().type.id == "iron_ore");
+    // No belt at the output port, so the produced item emerges and stays on the
+    // building's virtual output belt (REQ-MAT-OUTPUT-EMERGE).
+    const std::vector<Item> out = outputSideItems(*b);
+    REQUIRE(out.size() == 1);
+    REQUIRE(out.front().type.id == "iron_ore");
 }
 
 TEST_CASE("BuildingSystem: miner output buffer stalls when full", "[building]")
@@ -436,7 +455,9 @@ TEST_CASE("BuildingSystem: miner output buffer stalls when full", "[building]")
 
     const Building* b = bs.findBuilding(id);
     REQUIRE(b != nullptr);
-    REQUIRE(static_cast<int>(b->outputBuffer.items.size()) == 2);
+    // Both produced items are held on the output side (buffer + emerging lane),
+    // which is what the capacity rule counts (REQ-MAT-OUTPUT-EMERGE).
+    REQUIRE(b->outputItemCount() == 2);
     REQUIRE_FALSE(b->production.has_value());
 }
 
@@ -474,7 +495,8 @@ TEST_CASE("BuildingSystem: productionBuildingCount excludes construction sites",
     runTicks(bs, belts, static_cast<int>(secondsToTicks(15.0)), tick);
     REQUIRE(bs.productionBuildingCount() == 2);
 
-    // Neither has a recipe selected, so neither has an active cycle.
+    // Neither is producing yet: the miner has no recipe selected, and the
+    // smelter (auto-recipe, REQ-BLD-SMELTER) has no input feeding it.
     REQUIRE(bs.activeProductionBuildingCount() == 0);
 
     bs.setRecipe(minerId, "mine_iron_ore");
@@ -514,7 +536,7 @@ TEST_CASE("BuildingSystem: activeProductionBuildingCount tracks production cycle
 
     const Building* b = bs.findBuilding(id);
     REQUIRE(b != nullptr);
-    REQUIRE(static_cast<int>(b->outputBuffer.items.size()) == 2);
+    REQUIRE(b->outputItemCount() == 2);
     REQUIRE_FALSE(b->production.has_value());
     REQUIRE(bs.activeProductionBuildingCount() == 0);
 }
@@ -542,7 +564,8 @@ TEST_CASE("BuildingSystem: smelter input buffer fills from adjacent west-flowing
     // Smelter mask ["AA ","AA>"] → body (0,0),(1,0),(0,1),(1,1).
     // Output port (2,1) East.  Input port example: (2,0) West.
     const BuildingId sid = bs.place(BuildingType::Smelter, QPoint(0, 0), Rotation::East, 0);
-    bs.setRecipe(sid, "iron_ingot");
+    // Smelters have no recipe selection (REQ-BLD-SMELTER); they auto-accept any
+    // ore/scrap that is an input to a smelter recipe.
 
     // Complete construction (15s → tick 450+1 = 451 ticks).
     Tick tick = 0;
@@ -557,10 +580,192 @@ TEST_CASE("BuildingSystem: smelter input buffer fills from adjacent west-flowing
 
     const Building* b = bs.findBuilding(sid);
     REQUIRE(b != nullptr);
-    const std::map<ItemType, int>::const_iterator it =
+    // The item was accepted; it may still be travelling inward on the input belt,
+    // so count buffered + in-transit (REQ-MAT-INPUT-INTAKE).
+    REQUIRE(b->pendingInputCount(ItemType{"iron_ore"}) >= 1);
+}
+
+// An accepted input item travels inward on its input belt before it becomes usable
+// stock: it is reserved (counts against the cap) on entry and only enters the
+// buffer on reaching the tile centre (REQ-MAT-INPUT-INTAKE).
+TEST_CASE("BuildingSystem: accepted input travels inward before entering the buffer",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(static_cast<double>(kTickRateHz));  // fast belt: 1 tile/tick
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    const BuildingId sid = bs.place(BuildingType::Smelter, QPoint(0, 0), Rotation::East, 0);
+    Tick tick = 0;
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(15.0)) + 1, tick);
+
+    belts.placeBelt(QPoint(2, 0), Rotation::West);
+    belts.tryPutItem(QPoint(2, 0), makeItem("iron_ore"));
+    belts.tick();
+    bs.tickBeltPull();  // accepts the item onto the input belt at progress 0.0
+
+    const Building* b = bs.findBuilding(sid);
+    REQUIRE(b != nullptr);
+    // Reserved but not yet consumable: nothing in the buffer, but it counts against
+    // the cap via pendingInputCount.
+    const std::map<ItemType, int>::const_iterator it0 =
         b->inputBuffer.counts.find(ItemType{"iron_ore"});
-    REQUIRE(it != b->inputBuffer.counts.end());
-    REQUIRE(it->second >= 1);
+    REQUIRE((it0 == b->inputBuffer.counts.end() || it0->second == 0));
+    REQUIRE(b->pendingInputCount(ItemType{"iron_ore"}) == 1);
+
+    // One more pull tick advances the input belt to the centre; the item arrives.
+    bs.tickBeltPull();
+    REQUIRE(b->inputBuffer.counts.at(ItemType{"iron_ore"}) == 1);
+    REQUIRE(b->pendingInputCount(ItemType{"iron_ore"}) == 1);
+}
+
+// The acceptance test counts in-transit items, so buffered + reserved never exceeds
+// the per-material cap; excess items stay on the belt (REQ-MAT-INPUT-INTAKE).
+TEST_CASE("BuildingSystem: input reservation caps buffered plus in-transit at the cap",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(static_cast<double>(kTickRateHz));  // fast belt
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    const BuildingId id = bs.place(BuildingType::ReprocessingPlant,
+                                  QPoint(0, 0), Rotation::East, 0);
+    Tick tick = 0;
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(25.0)) + 1, tick);
+
+    // Feed scrap via an input belt without ever running production (only pull), so
+    // the buffer fills and stays full. Try to over-fill it well past the cap.
+    belts.placeBelt(QPoint(-1, 0), Rotation::East);
+    for (int i = 0; i < 20; ++i)
+    {
+        belts.tryPutItem(QPoint(-1, 0), makeItem("scrap"), Rotation::East);
+        belts.tick();
+        bs.tickBeltPull();
+    }
+
+    const Building* b = bs.findBuilding(id);
+    REQUIRE(b != nullptr);
+    const int cap = b->inputBuffer.caps.at(ItemType{"scrap"});
+    REQUIRE(cap > 0);
+    // buffered + in-transit is capped; the plant never over-pulls.
+    REQUIRE(b->pendingInputCount(ItemType{"scrap"}) == cap);
+    // Excess scrap is left stuck on the feeding belt rather than silently dropped.
+    REQUIRE(belts.peekItem(eastPort(QPoint(-1, 0))).has_value());
+}
+
+// A smelter auto-selects the matching recipe for whatever it is fed, with no
+// player recipe selection (REQ-BLD-SMELTER).
+TEST_CASE("BuildingSystem: smelter auto-smelts ore without a recipe selection",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(static_cast<double>(kTickRateHz));
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    const BuildingId sid = bs.place(BuildingType::Smelter, QPoint(0, 0), Rotation::East, 0);
+
+    Tick tick = 0;
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(15.0)) + 1, tick);
+
+    // Feed 2 iron_ore (the test-config iron_ingot recipe needs 2) via a
+    // west-flowing belt at input port (2,0).
+    belts.placeBelt(QPoint(2, 0), Rotation::West);
+    for (int i = 0; i < 2; ++i)
+    {
+        belts.tryPutItem(QPoint(2, 0), makeItem("iron_ore"));
+        belts.tick();
+        bs.tickBeltPull();
+    }
+
+    // iron_ingot recipe cycle is 2s; run to completion.
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(2.0)) + 2, tick);
+
+    const Building* b = bs.findBuilding(sid);
+    REQUIRE(b != nullptr);
+    bool hasIronIngot = false;
+    for (const Item& item : outputSideItems(*b))
+    {
+        if (item.type.id == "iron_ingot") { hasIronIngot = true; }
+    }
+    REQUIRE(hasIronIngot);
+}
+
+// With mixed inputs, the smelter runs whichever recipe is currently satisfiable
+// and leaves an incomplete batch of another input waiting (see the union-of-
+// inputs caps in initAutoBuffers).
+TEST_CASE("BuildingSystem: smelter runs a satisfiable recipe while an incomplete batch waits",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(static_cast<double>(kTickRateHz));
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    const BuildingId sid = bs.place(BuildingType::Smelter, QPoint(0, 0), Rotation::East, 0);
+
+    Tick tick = 0;
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(15.0)) + 1, tick);
+
+    // Feed 1 iron_ore (iron_ingot needs 2 — incomplete) then 2 copper_ore
+    // (copper_ingot needs 2 — satisfiable) via the west-flowing input belt.
+    belts.placeBelt(QPoint(2, 0), Rotation::West);
+    const char* fed[] = { "iron_ore", "copper_ore", "copper_ore" };
+    for (const char* id : fed)
+    {
+        belts.tryPutItem(QPoint(2, 0), makeItem(id));
+        belts.tick();
+        bs.tickBeltPull();
+    }
+
+    // copper_ingot cycle is 2.5s; run to completion.
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(2.5)) + 2, tick);
+
+    const Building* b = bs.findBuilding(sid);
+    REQUIRE(b != nullptr);
+
+    // Copper was smelted; the lone iron_ore still waits for a second unit.
+    bool hasCopperIngot = false;
+    for (const Item& item : outputSideItems(*b))
+    {
+        if (item.type.id == "copper_ingot") { hasCopperIngot = true; }
+    }
+    REQUIRE(hasCopperIngot);
+
+    const std::map<ItemType, int>::const_iterator ironIt =
+        b->inputBuffer.counts.find(ItemType{"iron_ore"});
+    REQUIRE(ironIt != b->inputBuffer.counts.end());
+    REQUIRE(ironIt->second == 1);
 }
 
 // ---------------------------------------------------------------------------
@@ -602,6 +807,84 @@ TEST_CASE("BuildingSystem: miner output buffer drains onto adjacent belt", "[bui
     REQUIRE(item->type.id == "iron_ore");
 }
 
+// Two directly adjacent buildings whose ports meet transfer items with no belt in
+// between: a miner's iron_ore output feeds straight into a smelter, which smelts it
+// (REQ-MAT-DIRECT-COUPLE).
+TEST_CASE("BuildingSystem: output port couples directly into an adjacent input port",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(cfg.world.beltSpeed_tps);
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    // Miner at (0,0): body (0,0),(1,0),(0,1); output port tile (1,1) flowing East.
+    const BuildingId minerId = bs.place(BuildingType::Miner, QPoint(0, 0), Rotation::East, 0);
+    bs.setRecipe(minerId, "mine_iron_ore");
+    // Smelter anchored at (1,1): body (1,1),(2,1),(1,2),(2,2). Its body cell (1,1) is
+    // the miner's output-port tile, and its west input edge there faces East, so the
+    // two ports meet — no belt placed anywhere.
+    const BuildingId smelterId = bs.place(BuildingType::Smelter, QPoint(1, 1), Rotation::East, 0);
+
+    Tick tick = 0;
+    // Smelter build (15s) + margin for coupling and a smelt cycle.
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(30.0)), tick);
+
+    const Building* smelter = bs.findBuilding(smelterId);
+    REQUIRE(smelter != nullptr);
+    // iron_ore reached the smelter over the direct coupling and was smelted.
+    bool hasIronIngot = false;
+    for (const Item& produced : outputSideItems(*smelter))
+    {
+        if (produced.type.id == "iron_ingot") { hasIronIngot = true; }
+    }
+    REQUIRE(hasIronIngot);
+}
+
+// A producer coupled to a building that cannot accept its item delivers nothing; the
+// item stays stuck at the producer's output port (REQ-MAT-DIRECT-COUPLE acceptance).
+TEST_CASE("BuildingSystem: direct coupling to a non-consumer leaves the item stuck",
+          "[building]")
+{
+    const GameConfig cfg = loadConfig();
+    BeltSystem belts(cfg.world.beltSpeed_tps);
+    int stock = 0;
+    std::mt19937 rng(0);
+    BuildingId nextBuildingId = 1;
+    BuildingSystem bs(cfg, belts,
+                      [&nextBuildingId]() { return nextBuildingId++; },
+                      [&stock](int n) { stock += n; },
+                      [](const std::string&, QVector2D, const std::optional<ShipLayoutConfig>&) {},
+                      [](const std::string&) -> bool { return true; },
+                      rng);
+
+    // Producing miner at (0,0), output port (1,1) East.
+    const BuildingId minerId = bs.place(BuildingType::Miner, QPoint(0, 0), Rotation::East, 0);
+    bs.setRecipe(minerId, "mine_iron_ore");
+    // A second, idle miner anchored at (1,1) occupies the output-port tile but takes
+    // no inputs, so it cannot accept the iron_ore.
+    const BuildingId sinkId = bs.place(BuildingType::Miner, QPoint(1, 1), Rotation::East, 0);
+
+    Tick tick = 0;
+    // Both miners build sequentially (10s each), then the producer runs and jams.
+    runTicks(bs, belts, static_cast<int>(secondsToTicks(25.0)), tick);
+
+    const Building* miner = bs.findBuilding(minerId);
+    const Building* sink  = bs.findBuilding(sinkId);
+    REQUIRE(miner != nullptr);
+    REQUIRE(sink != nullptr);
+    // Nothing was delivered, and the producer's output side has backed up to its cap.
+    REQUIRE(sink->pendingInputCount(ItemType{"iron_ore"}) == 0);
+    REQUIRE(miner->outputItemCount() == miner->outputBuffer.capacity);
+}
+
 // ---------------------------------------------------------------------------
 // setRecipe clears buffers
 // ---------------------------------------------------------------------------
@@ -633,13 +916,15 @@ TEST_CASE("BuildingSystem: setRecipe clears output buffer and active production"
     {
         const Building* b = bs.findBuilding(id);
         REQUIRE(b != nullptr);
-        REQUIRE_FALSE(b->outputBuffer.items.empty());
+        REQUIRE(b->outputItemCount() > 0);
     }
 
     bs.setRecipe(id, "mine_copper_ore");
 
     const Building* b = bs.findBuilding(id);
-    REQUIRE(b->outputBuffer.items.empty());
+    // Clearing the output buffer on a recipe change also discards emerging items
+    // (REQ-MAT-OUTPUT-EMERGE).
+    REQUIRE(b->outputItemCount() == 0);
     REQUIRE_FALSE(b->production.has_value());
 }
 
@@ -664,7 +949,8 @@ TEST_CASE("BuildingSystem: reprocessing plant output buffer capacity equals max
 
     const BuildingId id = bs.place(BuildingType::ReprocessingPlant,
                                   QPoint(0, 0), Rotation::East, 0);
-    bs.setRecipe(id, "reprocessing_cycle");
+    // Reprocessing plants have no recipe selection (REQ-BLD-REPROCESSING); the
+    // single reprocessing recipe is applied automatically on completion.
 
     // Complete construction (25s).
     Tick tick = 0;
@@ -695,7 +981,8 @@ TEST_CASE("BuildingSystem: reprocessing plant produces one cycle output then sta
 
     const BuildingId id = bs.place(BuildingType::ReprocessingPlant,
                                   QPoint(0, 0), Rotation::East, 0);
-    bs.setRecipe(id, "reprocessing_cycle");
+    // Reprocessing plants have no recipe selection (REQ-BLD-REPROCESSING); the
+    // single reprocessing recipe is applied automatically on completion.
 
     // Complete construction (25s).
     Tick tick = 0;
@@ -707,19 +994,17 @@ TEST_CASE("BuildingSystem: reprocessing plant produces one cycle output then sta
     belts.placeBelt(QPoint(-1, 0), Rotation::East);
     for (int i = 0; i < 5; ++i)
     {
-        belts.tryPutItem(QPoint(-1, 0), makeItem("scrap"));
+        belts.tryPutItem(QPoint(-1, 0), makeItem("scrap"), Rotation::East);
         belts.tick();
         bs.tickBeltPull();
     }
 
-    // Verify scrap is in input buffer.
+    // Verify all five scrap were accepted; some may still be travelling inward on
+    // the input belt (REQ-MAT-INPUT-INTAKE), so count buffered + in-transit.
     {
         const Building* b = bs.findBuilding(id);
         REQUIRE(b != nullptr);
-        const std::map<ItemType, int>::const_iterator it =
-            b->inputBuffer.counts.find(ItemType{"scrap"});
-        REQUIRE(it != b->inputBuffer.counts.end());
-        REQUIRE(it->second == 5);
+        REQUIRE(b->pendingInputCount(ItemType{"scrap"}) == 5);
     }
 
     // Run production cycle (3s = 90 ticks + 1 for the completion tick).

src/test/CMakeLists.txt

@@ -9,6 +9,7 @@ add_files(
     BeltSystemTest.cpp
     SurfaceMaskTest.cpp
     BuildingTest.cpp
+    BuildingConfigTest.cpp
     ShipTest.cpp
     ScrapTest.cpp
     BehaviorSystemTest.cpp
@@ -21,6 +22,7 @@ add_files(
     ShipModuleTest.cpp
     ThreatCostCalculatorTest.cpp
     RecipeSchematicTest.cpp
+    UnlockPrereqTest.cpp
     ArtifactWinConditionTest.cpp
     DeterminismTest.cpp
     CommandTest.cpp

src/test/ConfigLoaderTest.cpp

@@ -6,6 +6,7 @@
 #include <stdexcept>
 #include <string>
 #include <system_error>
+#include <vector>
 
 #include "BuildingType.h"
 #include "ConfigLoader.h"
@@ -75,11 +76,18 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     REQUIRE(cfg.world.regions.playerBufferWidth_tiles == 10);
     REQUIRE(cfg.world.regions.enemyBufferWidth_tiles == 15);
     REQUIRE(cfg.world.expansion.columnsPerExpansion_tiles == 10);
+    REQUIRE(cfg.world.expansion.costBuildingBlocksFormula.evaluate(0) == Approx(400.0));
+    REQUIRE(cfg.world.expansion.costBuildingBlocksFormula.evaluate(1) == Approx(800.0));
     REQUIRE(cfg.world.push.bossAdvanceSeconds == Approx(60.0));
     REQUIRE(cfg.world.orbitFactor == Approx(0.8));
     REQUIRE(cfg.world.rallyOrbitRadius_tiles == Approx(5.0));
     REQUIRE(cfg.world.scrapPerThreat == Approx(1.0));
 
+    // Optional header building blocks tooltip (REQ-UI-BLOCKS-TOOLTIP).
+    REQUIRE(cfg.world.buildingBlocksTooltip.has_value());
+    REQUIRE(*cfg.world.buildingBlocksTooltip ==
+            "Spend building blocks to build; deliver them to the HQ to gain more.");
+
     // Spot-check that a config-derived formula computes as expected.
     // threat_rate_formula = "x": evaluates to the input value.
     REQUIRE(cfg.world.waves.threatRateFormula.evaluate(1.0) == Approx(1.0));
@@ -100,6 +108,21 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     REQUIRE(minerIt != cfg.buildings.buildings.end());
     REQUIRE(minerIt->cost == 15);
     REQUIRE(minerIt->surfaceMask.size() == 2);
+    // Miner has no output-buffer-capacity override; the Salvage Bay does.
+    REQUIRE_FALSE(minerIt->outputBufferCapacity.has_value());
+
+    const auto salvageBayIt = std::find_if(
+        cfg.buildings.buildings.begin(), cfg.buildings.buildings.end(),
+        [](const BuildingDef& b) { return b.type == BuildingType::SalvageBay; });
+    REQUIRE(salvageBayIt != cfg.buildings.buildings.end());
+    REQUIRE(salvageBayIt->outputBufferCapacity.has_value());
+    REQUIRE(*salvageBayIt->outputBufferCapacity == 20);
+
+    // Optional per-building tooltip (REQ-UI-BUILD-TOOLTIP): the Salvage Bay
+    // defines one; the Miner leaves it unset.
+    REQUIRE(salvageBayIt->tooltip.has_value());
+    REQUIRE(*salvageBayIt->tooltip == "Drop-off point for salvage ships.");
+    REQUIRE_FALSE(minerIt->tooltip.has_value());
 
     // recipes.toml — reprocessing cycle has three weighted outputs.
     const auto reproIt = std::find_if(
@@ -132,6 +155,21 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     REQUIRE(salvageShipIt != cfg.ships.ships.end());
     REQUIRE(salvageShipIt->defaultModules.empty());
 
+    // modules.toml — optional per-module tooltip (REQ-MOD-UI-MODULE-TOOLTIP):
+    // armor_plate defines one; salvager leaves it unset.
+    const auto armorPlateIt = std::find_if(
+        cfg.modules.modules.begin(), cfg.modules.modules.end(),
+        [](const ModuleDef& m) { return m.id == "armor_plate"; });
+    REQUIRE(armorPlateIt != cfg.modules.modules.end());
+    REQUIRE(armorPlateIt->tooltip.has_value());
+    REQUIRE(*armorPlateIt->tooltip == "Adds a large flat bonus to hit points.");
+
+    const auto salvagerModuleIt = std::find_if(
+        cfg.modules.modules.begin(), cfg.modules.modules.end(),
+        [](const ModuleDef& m) { return m.id == "salvager"; });
+    REQUIRE(salvagerModuleIt != cfg.modules.modules.end());
+    REQUIRE_FALSE(salvagerModuleIt->tooltip.has_value());
+
     // stations.toml
     REQUIRE(cfg.stations.playerStation.level == 5);
     REQUIRE(cfg.stations.playerStation.hpFormula.evaluate(5.0) == Approx(500.0));  // 300 + 40*5
@@ -185,7 +223,7 @@ contest_zone_width_tiles = 30
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20
@@ -236,7 +274,7 @@ enemy_buffer_width_tiles = 15
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20
@@ -283,7 +321,7 @@ enemy_buffer_width_tiles = 15
 
 [expansion]
 columns_per_expansion_tiles = 10
-cost_building_blocks = 200
+cost_building_blocks_formula = "400 * 2^x"
 
 [push]
 push_expand_columns_tiles = 20
@@ -343,3 +381,151 @@ duration_seconds = 1.0
         std::runtime_error);
 }
 
+// --- unlock_requires (REQ-LOCK-PREREQ) ------------------------------------
+
+namespace
+{
+
+// Copies every regular file from CONFIG_DIR into dir, giving tests a full,
+// valid config set they can then perturb before calling loadFromDirectory.
+void copyConfigInto(const std::filesystem::path& dir)
+{
+    for (const std::filesystem::directory_entry& entry :
+         std::filesystem::directory_iterator(std::string(CONFIG_DIR)))
+    {
+        if (entry.is_regular_file())
+        {
+            std::filesystem::copy_file(entry.path(), dir / entry.path().filename());
+        }
+    }
+}
+
+} // namespace
+
+TEST_CASE("unlock_requires parses into a ship def", "[config]")
+{
+    TempConfigDir dir;
+    writeFile(dir.path() / "ships.toml", R"(
+[[ship]]
+id = "alpha"
+unlock_at_station_level = 1
+unlock_requires = ["beta", "gamma"]
+layout = ["O"]
+[ship.schematic]
+materials = []
+production_time_seconds = 5
+[ship.health]
+hp = 10
+[ship.movement]
+speed_mps = 1
+main_acceleration_mpss = 1
+maneuvering_acceleration_mpss = 1
+angular_acceleration_radpss = 1
+max_rotation_speed_radps = 1
+[ship.sensor]
+sensor_range_m = 10
+)");
+
+    const ShipsConfig cfg = ConfigLoader::loadShips((dir.path() / "ships.toml").string());
+    REQUIRE(cfg.ships.size() == 1);
+    CHECK(cfg.ships[0].unlockRequires == std::vector<std::string>{"beta", "gamma"});
+}
+
+TEST_CASE("unlock_requires parses into a module def", "[config]")
+{
+    TempConfigDir dir;
+    writeFile(dir.path() / "modules.toml", R"(
+[[module]]
+id = "m1"
+unlock_at_station_level = 0
+unlock_requires = ["dep"]
+surface_mask = ["O"]
+materials = [{item = "iron_ingot", amount = 1}]
+production_time_seconds = 1
+fill_color = "#ffffff"
+glyph = "M"
+)");
+
+    const ModulesConfig cfg = ConfigLoader::loadModules((dir.path() / "modules.toml").string());
+    REQUIRE(cfg.modules.size() == 1);
+    CHECK(cfg.modules[0].unlockRequires == std::vector<std::string>{"dep"});
+}
+
+TEST_CASE("unlock_requires parses only for assembler recipes", "[config]")
+{
+    TempConfigDir dir;
+    writeFile(dir.path() / "recipes.toml", R"(
+[[recipe]]
+id = "gated_asm"
+building = "assembler"
+unlock_at_station_level = 1
+unlock_requires = ["prereq_recipe"]
+inputs = []
+outputs = [{item = "foo", amount = 1}]
+duration_seconds = 1.0
+
+[[recipe]]
+id = "a_miner"
+building = "miner"
+unlock_requires = ["ignored"]
+inputs = []
+outputs = [{item = "ore", amount = 1}]
+duration_seconds = 1.0
+)");
+
+    const RecipesConfig cfg = ConfigLoader::loadRecipes((dir.path() / "recipes.toml").string());
+    REQUIRE(cfg.recipes.size() == 2);
+    CHECK(cfg.recipes[0].unlockRequires == std::vector<std::string>{"prereq_recipe"});
+    // The field is only consumed for assembler recipe schematics; a miner recipe
+    // leaves it unparsed (empty).
+    CHECK(cfg.recipes[1].unlockRequires.empty());
+}
+
+TEST_CASE("unlock_requires referencing an unknown schematic is rejected at load", "[config]")
+{
+    TempConfigDir dir;
+    copyConfigInto(dir.path());
+
+    std::ofstream out((dir.path() / "recipes.toml").string(), std::ios::app);
+    out << "\n[[recipe]]\n"
+           "id = \"gated_bogus\"\n"
+           "building = \"assembler\"\n"
+           "unlock_at_station_level = 1\n"
+           "unlock_requires = [\"___does_not_exist___\"]\n"
+           "inputs = []\n"
+           "outputs = [{item = \"circuit_board\", amount = 1}]\n"
+           "duration_seconds = 1.0\n";
+    out.close();
+
+    try
+    {
+        ConfigLoader::loadFromDirectory(dir.path().string());
+        FAIL("Expected exception");
+    }
+    catch (const std::runtime_error& e)
+    {
+        const std::string msg = e.what();
+        REQUIRE(msg.find("___does_not_exist___") != std::string::npos);
+    }
+}
+
+TEST_CASE("unlock_requires referencing a real schematic loads without error", "[config]")
+{
+    TempConfigDir dir;
+    copyConfigInto(dir.path());
+
+    // "interceptor" is a ship schematic in the test config — a valid prerequisite.
+    std::ofstream out((dir.path() / "recipes.toml").string(), std::ios::app);
+    out << "\n[[recipe]]\n"
+           "id = \"gated_ok\"\n"
+           "building = \"assembler\"\n"
+           "unlock_at_station_level = 1\n"
+           "unlock_requires = [\"interceptor\"]\n"
+           "inputs = []\n"
+           "outputs = [{item = \"circuit_board\", amount = 1}]\n"
+           "duration_seconds = 1.0\n";
+    out.close();
+
+    REQUIRE_NOTHROW(ConfigLoader::loadFromDirectory(dir.path().string()));
+}
+

src/test/RecipeSchematicTest.cpp

@@ -283,7 +283,7 @@ TEST_CASE("RecipeSchematic: reset keeps -1 recipes unlocked and their seed items
 // Unlock dialog: newly-unlocked recipe preview (REQ-DEF-SCHEMATIC-DROP)
 // ---------------------------------------------------------------------------
 
-TEST_CASE("RecipeSchematic: newlyUnlockedItemNames is sorted, deduplicated, and empty for level-ups",
+TEST_CASE("RecipeSchematic: newlyUnlockedRecipeIds is sorted, deduplicated, and empty for level-ups",
           "[recipe_schematic]")
 {
     Simulation sim(loadConfig());
@@ -295,10 +295,11 @@ TEST_CASE("RecipeSchematic: newlyUnlockedItemNames is sorted, deduplicated, and
 
         for (const SchematicChoiceOption& opt : sim.getPendingSchematicChoices())
         {
-            // Strictly ascending implies sorted and deduplicated.
-            for (std::size_t j = 1; j < opt.newlyUnlockedItemNames.size(); ++j)
+            // Strictly ascending display names imply sorted and deduplicated.
+            for (std::size_t j = 1; j < opt.newlyUnlockedRecipeIds.size(); ++j)
             {
-                CHECK(opt.newlyUnlockedItemNames[j - 1] < opt.newlyUnlockedItemNames[j]);
+                CHECK(toDisplayName(opt.newlyUnlockedRecipeIds[j - 1])
+                      < toDisplayName(opt.newlyUnlockedRecipeIds[j]));
             }
         }
 
@@ -306,7 +307,7 @@ TEST_CASE("RecipeSchematic: newlyUnlockedItemNames is sorted, deduplicated, and
     }
 }
 
-TEST_CASE("RecipeSchematic: newlyUnlockedItemNames matches recipes that actually become unlocked",
+TEST_CASE("RecipeSchematic: newlyUnlockedRecipeIds matches recipes that actually become unlocked",
           "[recipe_schematic]")
 {
     Simulation sim(loadConfig());
@@ -336,21 +337,22 @@ TEST_CASE("RecipeSchematic: newlyUnlockedItemNames matches recipes that actually
 
         SimulationTestAccess::applySchematicChoice(sim, 0);
 
-        std::set<std::string> expectedNames;
+        std::vector<std::string> expected;
         for (const RecipeDef& def : cfg.recipes.recipes)
         {
             if ((def.building == BuildingType::Miner || def.building == BuildingType::Assembler)
                 && sim.isRecipeUnlocked(def.id) && unlockedBefore.count(def.id) == 0)
             {
-                for (const RecipeOutput& out : def.outputs)
-                {
-                    expectedNames.insert(toDisplayName(out.item));
-                }
+                expected.push_back(def.id);
             }
         }
-        const std::vector<std::string> expected(expectedNames.begin(), expectedNames.end());
+        std::sort(expected.begin(), expected.end(),
+                  [](const std::string& lhs, const std::string& rhs)
+                  {
+                      return toDisplayName(lhs) < toDisplayName(rhs);
+                  });
 
-        REQUIRE(choice.newlyUnlockedItemNames == expected);
+        REQUIRE(choice.newlyUnlockedRecipeIds == expected);
     }
 }
 

src/test/ScrapTest.cpp

@@ -2,11 +2,22 @@
 
 #include <QVector2D>
 
+#include <algorithm>
+
 #include "DespawnAtComponent.h"
 #include "EntityAdmin.h"
+#include "EntityHitTest.h"
 #include "ScrapDataComponent.h"
 #include "ScrapSystem.h"
 
+namespace
+{
+bool contains(const std::vector<entt::entity>& v, entt::entity e)
+{
+    return std::find(v.begin(), v.end(), e) != v.end();
+}
+} // namespace
+
 // ---------------------------------------------------------------------------
 // Spawn
 // ---------------------------------------------------------------------------
@@ -140,3 +151,78 @@ TEST_CASE("ScrapSystem: allScrapInfo returns all spawned scrap", "[scrap]")
     const std::vector<ScrapInfo> info = ss.allScrapInfo();
     REQUIRE(info.size() == 2);
 }
+
+TEST_CASE("ScrapSystem: allScrapInfo reports each pile's remaining amount", "[scrap]")
+{
+    EntityAdmin admin;
+    ScrapSystem ss(admin);
+
+    const entt::entity a = ss.spawn(QVector2D(1.0f, 2.0f), 3, 100);
+    const entt::entity b = ss.spawn(QVector2D(4.0f, 5.0f), 6, 200);
+
+    const std::vector<ScrapInfo> info = ss.allScrapInfo();
+    REQUIRE(info.size() == 2);
+    for (const ScrapInfo& i : info)
+    {
+        if (i.entity == a) { REQUIRE(i.amount == 3); }
+        else if (i.entity == b) { REQUIRE(i.amount == 6); }
+        else { FAIL("unexpected scrap entity"); }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Selection hit-testing (REQ-UI-SCRAP-CLICK-SELECT, REQ-UI-SCRAP-MULTI-SELECT)
+// ---------------------------------------------------------------------------
+
+TEST_CASE("scrapAtWorldPos returns the pile near a point and null when far", "[scrap]")
+{
+    EntityAdmin admin;
+    ScrapSystem ss(admin);
+
+    const entt::entity e = ss.spawn(QVector2D(3.0f, 4.0f), 5, 100);
+
+    // Extra parens keep Catch from decomposing the comparison, which is ambiguous
+    // between Catch's expression templates and entt's entity operator==.
+    REQUIRE((scrapAtWorldPos(admin, QVector2D(3.1f, 4.0f)) == e));
+    REQUIRE((scrapAtWorldPos(admin, QVector2D(10.0f, 10.0f)) == entt::null));
+}
+
+TEST_CASE("scrapAtWorldPos returns the nearest of several piles", "[scrap]")
+{
+    EntityAdmin admin;
+    ScrapSystem ss(admin);
+
+    const entt::entity near = ss.spawn(QVector2D(2.0f, 2.0f), 1, 100);
+    ss.spawn(QVector2D(2.4f, 2.0f), 1, 100);
+
+    REQUIRE((scrapAtWorldPos(admin, QVector2D(2.05f, 2.0f)) == near));
+}
+
+TEST_CASE("entityAtWorldPos never returns a scrap pile", "[scrap]")
+{
+    EntityAdmin admin;
+    ScrapSystem ss(admin);
+
+    ss.spawn(QVector2D(3.0f, 4.0f), 5, 100);
+
+    // Scrap has no HealthComponent, so the actor hit-test ignores it entirely.
+    REQUIRE((entityAtWorldPos(admin, QVector2D(3.0f, 4.0f)) == entt::null));
+}
+
+TEST_CASE("scrapInBox returns exactly the piles inside the tile rectangle", "[scrap]")
+{
+    EntityAdmin admin;
+    ScrapSystem ss(admin);
+
+    const entt::entity inA  = ss.spawn(QVector2D(1.2f, 2.7f), 1, 100); // tile (1,2)
+    const entt::entity inB  = ss.spawn(QVector2D(4.9f, 5.1f), 1, 100); // tile (4,5)
+    const entt::entity outX = ss.spawn(QVector2D(10.0f, 10.0f), 1, 100);
+
+    // Box given in reversed corner order to confirm normalization.
+    const std::vector<entt::entity> hit = scrapInBox(admin, QPoint(5, 5), QPoint(0, 0));
+
+    REQUIRE(hit.size() == 2);
+    REQUIRE(contains(hit, inA));
+    REQUIRE(contains(hit, inB));
+    REQUIRE_FALSE(contains(hit, outX));
+}

src/test/ShipModuleTest.cpp

@@ -6,6 +6,7 @@
 #include "ConfigLoader.h"
 #include "DynamicBodyComponent.h"
 #include "EntityAdmin.h"
+#include "FactionComponent.h"
 #include "GameConfig.h"
 #include "HealthComponent.h"
 #include "ItemType.h"
@@ -13,6 +14,7 @@
 #include "ModulesConfig.h"
 #include "Rotation.h"
 #include "SensorRangeComponent.h"
+#include "ShipIdentityComponent.h"
 #include "ShipLayout.h"
 #include "ShipStatsCalculator.h"
 #include "ShipSystem.h"
@@ -264,6 +266,50 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
     CHECK_FALSE(b2->production.has_value());
 }
 
+TEST_CASE("Shipyard: builds a bare hull when no layout is configured",
+          "[modules][shipyard]")
+{
+    Simulation sim(loadConfig(), 42);
+    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    REQUIRE(def != nullptr);
+    // The schematic carries a weapon in its (wave-only) default loadout. This
+    // test pins that a player shipyard with no configured layout does NOT hand
+    // that weapon out for free: it builds an unarmed bare hull, matching the
+    // base-hull materials it was charged.
+    REQUIRE_FALSE(def->defaultModules.empty());
+
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(yardId, "interceptor");
+    // Deliberately no setShipLayout: recipe set, layout left unconfigured.
+
+    // Charge only the base-hull materials (an empty layout adds none).
+    fillMaterials(sim, yardId, *def, ShipLayoutConfig{});
+
+    // Tick through one full production cycle so the ship spawns.
+    const Tick cycleTicks = secondsToTicks(def->schematic.productionTimeSeconds);
+    for (Tick i = 0; i <= cycleTicks; ++i)
+    {
+        sim.tick();
+    }
+
+    // Locate the freshly built player ship.
+    entt::entity built = entt::null;
+    sim.admin().forEach<ShipIdentityComponent, FactionComponent>(
+        [&](entt::entity e, const ShipIdentityComponent& si, const FactionComponent& fac)
+        {
+            if (!fac.isEnemy && si.schematicId == "interceptor") { built = e; }
+        });
+    REQUIRE(sim.admin().isValid(built));
+
+    // Bare hull: the schematic's default weapon must NOT have been installed.
+    const bool hasWeapon =
+        findFirstWeaponChild(sim.admin(), built) != entt::null;
+    CHECK_FALSE(hasWeapon);
+}
+
 TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
@@ -292,6 +338,38 @@ TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
     CHECK_FALSE(b2->shipLayout.has_value());
 }
 
+TEST_CASE("Shipyard: setRecipe with unchanged recipe keeps ship layout",
+          "[modules][shipyard]")
+{
+    Simulation sim(loadConfig(), 42);
+    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    REQUIRE(yardDef != nullptr);
+
+    const BuildingId yardId = placeShipyard(sim, *yardDef);
+    SimulationTestAccess::buildings(sim).setRecipe(yardId,"interceptor");
+
+    ShipLayoutConfig layout;
+    PlacedModule pm;
+    pm.moduleId = "armor_plate";
+    pm.position = QPoint(0, 0);
+    pm.rotation = Rotation::East;
+    layout.placedModules.push_back(pm);
+    SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
+
+    const Building* b1 = sim.buildings().findBuilding(yardId);
+    REQUIRE(b1 != nullptr);
+    REQUIRE(b1->shipLayout.has_value());
+
+    // Re-selecting the same recipe must be a no-op and preserve the layout.
+    SimulationTestAccess::buildings(sim).setRecipe(yardId,"interceptor");
+
+    const Building* b2 = sim.buildings().findBuilding(yardId);
+    REQUIRE(b2 != nullptr);
+    REQUIRE(b2->shipLayout.has_value());
+    REQUIRE(b2->shipLayout->placedModules.size() == 1);
+    CHECK(b2->shipLayout->placedModules[0].moduleId == "armor_plate");
+}
+
 // ---------------------------------------------------------------------------
 // Weapon modifier simulation tests
 // ---------------------------------------------------------------------------

src/test/ThreatCostCalculatorTest.cpp

@@ -107,3 +107,62 @@ TEST_CASE("ThreatCostCalculator: unknown ship returns zero", "[threat]")
     double threat = calculateShipThreatCost(table, cfg, "nonexistent_ship", {});
     CHECK(threat == Approx(0.0));
 }
+
+// Fix 6: scrap-consuming recipes are a fallback only.
+// iron_ingot has a scrap-free smelter recipe, so the scrap_iron recipe must
+// be excluded. iron_ingot threat must not be inflated by the scrap path.
+TEST_CASE("ThreatCostCalculator: scrap-consuming recipe excluded when scrap-free recipe exists", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    // scrap_iron recipe: duration=1.0, 1 scrap (threat=1.0) -> 1 iron_ingot.
+    // That would give 1.0 + 1.0*1 = 2.0 per unit — but it must be excluded
+    // because the scrap-free iron_ingot smelter recipe (threat=4.0) exists.
+    // iron_ingot threat stays at 4.0.
+    CHECK(table.itemThreat.at("iron_ingot") == Approx(4.0));
+
+    // The pure reprocessing-only item (advanced_alloy) must still be resolved
+    // via the reprocessing path.
+    CHECK(table.itemThreat.count("advanced_alloy") == 1u);
+}
+
+// Fix 7: per-unit item threat divides by output amount.
+// dual_wire: assembler, 1 iron_ore -> 2 dual_wire, duration 3.0.
+// Per-unit threat = (3.0 + iron_ore(1.0)*1) / 2 = 4.0 / 2 = 2.0.
+TEST_CASE("ThreatCostCalculator: per-unit division by output amount", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("dual_wire") == Approx(2.0));
+}
+
+// Fix 8: fixpoint resolution — items downstream of reprocessing-only items
+// must be resolved after the reprocessing pass re-enables the non-reprocessing
+// pass.
+// downstream_product: assembler, 1 advanced_alloy -> 1, duration 2.0.
+// advanced_alloy = 80.0 (reprocessing-only).
+// downstream_product = 2.0 + 80.0*1 = 82.0.
+TEST_CASE("ThreatCostCalculator: downstream-of-reprocessing item resolves via fixpoint", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("advanced_alloy") == Approx(80.0));
+    CHECK(table.itemThreat.at("downstream_product") == Approx(82.0));
+}
+
+// Fix 9: max rule across staggered recipes — item is committed only once
+// every eligible recipe for it is computable.
+// staggered_item has two recipes:
+//   cheap:     1 iron_ore (1.0) + 1.0 s  = 2.0  (resolves early)
+//   expensive: 1 circuit_board (28.0) + 1.0 s = 29.0  (resolves later)
+// expected threat = max(2.0, 29.0) = 29.0, not 2.0.
+TEST_CASE("ThreatCostCalculator: staggered recipes committed only when all computable", "[threat]")
+{
+    const GameConfig cfg = loadConfig();
+    const ThreatCostTable& table = cfg.threatCosts;
+
+    CHECK(table.itemThreat.at("staggered_item") == Approx(29.0));
+}

src/test/UnlockPrereqTest.cpp

@@ -0,0 +1,174 @@
+// Drop-pool behaviour for unlock_requires schematic prerequisites
+// (REQ-LOCK-PREREQ). A schematic enters the drop pool only when every id in its
+// unlock_requires is already explicitly unlocked, on top of the station-level
+// (and, for recipes, output-implicitly-unlocked) checks.
+//
+// Configs are built in memory (load the test config, then mutate) so each case
+// is isolated and does not perturb the shared test config used by other suites.
+
+#include <algorithm>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "catch.hpp"
+
+#include "ConfigLoader.h"
+#include "FactionComponent.h"
+#include "GameConfig.h"
+#include "HealthComponent.h"
+#include "ModulesConfig.h"
+#include "RecipesConfig.h"
+#include "SchematicChoiceOption.h"
+#include "ShipsConfig.h"
+#include "Simulation.h"
+#include "SimulationTestAccess.h"
+#include "StationBodyComponent.h"
+
+namespace
+{
+
+GameConfig loadConfig()
+{
+    return ConfigLoader::loadFromDirectory(CONFIG_DIR);
+}
+
+ShipDef& findShip(GameConfig& cfg, const std::string& id)
+{
+    for (ShipDef& def : cfg.ships.ships)
+    {
+        if (def.id == id) { return def; }
+    }
+    FAIL("ship not found: " + id);
+    return cfg.ships.ships.front();
+}
+
+ModuleDef& findModule(GameConfig& cfg, const std::string& id)
+{
+    for (ModuleDef& def : cfg.modules.modules)
+    {
+        if (def.id == id) { return def; }
+    }
+    FAIL("module not found: " + id);
+    return cfg.modules.modules.front();
+}
+
+RecipeDef& findRecipe(GameConfig& cfg, const std::string& id)
+{
+    for (RecipeDef& def : cfg.recipes.recipes)
+    {
+        if (def.id == id) { return def; }
+    }
+    FAIL("recipe not found: " + id);
+    return cfg.recipes.recipes.front();
+}
+
+// Zeros the HP of both enemy defence stations and advances one tick so that
+// tickDeathsAndLoot fires, triggering the push and schematic choices.
+void killEnemyStations(Simulation& sim)
+{
+    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+        [](entt::entity, StationBodyComponent&, FactionComponent& faction, HealthComponent& health)
+        {
+            if (faction.isEnemy)
+            {
+                health.hp = 0.0f;
+            }
+        });
+    sim.tick();
+}
+
+void killEnemyStationsAndApply(Simulation& sim)
+{
+    killEnemyStations(sim);
+    if (sim.hasSchematicChoicesPending())
+    {
+        SimulationTestAccess::applySchematicChoice(sim, 0);
+    }
+}
+
+bool optionOffered(const Simulation& sim, const std::string& id)
+{
+    const std::vector<SchematicChoiceOption>& options = sim.getPendingSchematicChoices();
+    return std::any_of(options.begin(), options.end(),
+        [&](const SchematicChoiceOption& o) { return o.schematicId == id; });
+}
+
+} // namespace
+
+TEST_CASE("UnlockPrereq: a recipe gated behind a locked ship is withheld from the pool",
+          "[unlock_prereq]")
+{
+    // quick_circuit (assembler recipe, level 0, output circuit_board is implicitly
+    // unlocked) would normally be eligible at the first station destruction. Gate
+    // it behind repair_ship (ship, level 0, locked at game start).
+    GameConfig cfg = loadConfig();
+    findRecipe(cfg, "quick_circuit").unlockRequires = {"repair_ship"};
+
+    Simulation sim(std::move(cfg), 123);
+    REQUIRE_FALSE(sim.isSchematicUnlocked("repair_ship"));
+
+    killEnemyStations(sim);  // destroyed set level 0
+    REQUIRE(sim.hasSchematicChoicesPending());
+
+    // Prerequisite unmet -> the gated recipe must not be offered, while the
+    // prerequisite schematic itself (the only other eligible pick) is.
+    CHECK_FALSE(optionOffered(sim, "quick_circuit"));
+    CHECK(optionOffered(sim, "repair_ship"));
+}
+
+TEST_CASE("UnlockPrereq: the gated recipe becomes eligible once its prerequisite is unlocked",
+          "[unlock_prereq]")
+{
+    GameConfig cfg = loadConfig();
+    findRecipe(cfg, "quick_circuit").unlockRequires = {"repair_ship"};
+
+    Simulation sim(std::move(cfg), 123);
+
+    // Applying choice 0 each drop unlocks repair_ship first (the only eligible
+    // pick at level 0), which then opens quick_circuit for a later drop.
+    bool unlocked = false;
+    for (int i = 0; i < 150 && !unlocked; ++i)
+    {
+        killEnemyStationsAndApply(sim);
+        unlocked = sim.isRecipeUnlocked("quick_circuit");
+    }
+
+    CHECK(sim.isSchematicUnlocked("repair_ship"));  // prerequisite got unlocked along the way
+    CHECK(unlocked);
+}
+
+TEST_CASE("UnlockPrereq: a module gated behind another module is withheld until it unlocks",
+          "[unlock_prereq]")
+{
+    // Mirror the app-config demo (laser_cannon_m -> laser_cannon_l) using two
+    // test-config modules made lockable at the same station level.
+    GameConfig cfg = loadConfig();
+    findModule(cfg, "laser_cannon").unlockAtStationLevel = 0;
+    ModuleDef& armor = findModule(cfg, "armor_plate");
+    armor.unlockAtStationLevel = 0;
+    armor.unlockRequires = {"laser_cannon"};
+
+    Simulation sim(std::move(cfg), 7);
+    REQUIRE_FALSE(sim.isModuleSchematicUnlocked("laser_cannon"));
+    REQUIRE_FALSE(sim.isModuleSchematicUnlocked("armor_plate"));
+
+    killEnemyStations(sim);  // level 0
+    REQUIRE(sim.hasSchematicChoicesPending());
+    // armor_plate is gated behind the still-locked laser_cannon module.
+    CHECK_FALSE(optionOffered(sim, "armor_plate"));
+
+    // Drive the drops until the gated module unlocks; it can only do so after its
+    // prerequisite has itself been unlocked.
+    bool armorUnlocked = false;
+    for (int i = 0; i < 300 && !armorUnlocked; ++i)
+    {
+        killEnemyStationsAndApply(sim);
+        armorUnlocked = sim.isModuleSchematicUnlocked("armor_plate");
+        if (armorUnlocked)
+        {
+            CHECK(sim.isModuleSchematicUnlocked("laser_cannon"));
+        }
+    }
+    CHECK(armorUnlocked);
+}

src/ui/BlueprintPanel.cpp

@@ -19,6 +19,7 @@
 #include "ExitBlueprintModeRequestedEvent.h"
 
 #include "Building.h"
+#include "BuildingConfig.h"
 #include "BuildingSystem.h"
 #include "Simulation.h"
 
@@ -53,23 +54,15 @@ BlueprintPanel::BlueprintPanel(Simulation* sim, const GameConfig* config, QWidge
 
     connect(m_createBtn, &QPushButton::clicked, this, &BlueprintPanel::onCreateClicked);
 
-    QHBoxLayout* ioLayout = new QHBoxLayout();
-    m_saveBtn = new QPushButton(tr("Save"), this);
-    m_loadBtn = new QPushButton(tr("Load"), this);
-    m_saveBtn->setFixedHeight(36);
-    m_loadBtn->setFixedHeight(36);
-    ioLayout->addWidget(m_saveBtn);
-    ioLayout->addWidget(m_loadBtn);
-    layout->addLayout(ioLayout);
-
-    connect(m_saveBtn, &QPushButton::clicked, this, &BlueprintPanel::onSaveClicked);
-    connect(m_loadBtn, &QPushButton::clicked, this, &BlueprintPanel::onLoadClicked);
+    loadFromDisk();
+    rebuildButtons();
 
     registerForEvents();
 }
 
 BlueprintPanel::~BlueprintPanel()
 {
+    saveToDisk();
     unregisterForEvents();
 }
 
@@ -153,67 +146,10 @@ void BlueprintPanel::onBlueprintButtonClicked(int index)
 
 Blueprint BlueprintPanel::createBlueprintFromSelection() const
 {
-    struct Entry
-    {
-        const Building* building;
-    };
-    std::vector<Entry> entries;
-    entries.reserve(m_selectedBuildingIds.size());
-
-    for (const BuildingId id : m_selectedBuildingIds)
-    {
-        const Building* b = m_sim->buildings().findBuilding(id);
-        if (!b) { continue; }
-        const bool placeable = [&]() {
-            for (const BuildingDef& def : m_config->buildings.buildings)
-            {
-                if (def.type == b->type) { return def.playerPlaceable; }
-            }
-            return false;
-        }();
-        if (placeable) { entries.push_back({ b }); }
-    }
-
-    if (entries.empty()) { return Blueprint{}; }
-
-    int minX = INT_MAX, maxX = INT_MIN;
-    int minY = INT_MAX, maxY = INT_MIN;
-    for (const Entry& e : entries)
-    {
-        for (const QPoint& cell : e.building->bodyCells)
-        {
-            minX = std::min(minX, cell.x());
-            maxX = std::max(maxX, cell.x());
-            minY = std::min(minY, cell.y());
-            maxY = std::max(maxY, cell.y());
-        }
-    }
-
-    const QPoint center((minX + maxX) / 2, (minY + maxY) / 2);
-
-    Blueprint bp;
-    bp.buildings.reserve(entries.size());
-    for (const Entry& e : entries)
-    {
-        BlueprintBuilding bb;
-        bb.type       = e.building->type;
-        bb.rotation   = e.building->rotation;
-        bb.offset     = e.building->anchor - center;
-        bb.recipeId   = e.building->recipeId;
-        bb.shipLayout = e.building->shipLayout;
-        if (e.building->type == BuildingType::Splitter)
-        {
-            const std::optional<BeltSystem::SplitterInfo> info =
-                m_sim->belts().getSplitterInfo(e.building->anchor);
-            if (info.has_value())
-            {
-                bb.splitterFilterA = info->filterA;
-                bb.splitterFilterB = info->filterB;
-            }
-        }
-        bp.buildings.push_back(bb);
-    }
-    return bp;
+    // Capture is shared, testable logic in lib/sim: it resolves each selected id as an
+    // operational building or a construction site alike (REQ-UI-BLUEPRINT-CREATE,
+    // REQ-UI-BLUEPRINT-STORAGE).
+    return captureBlueprintFromSelection(*m_sim, m_selectedBuildingIds);
 }
 
 int BlueprintPanel::computeBlueprintCost(const Blueprint& bp) const
@@ -221,14 +157,8 @@ int BlueprintPanel::computeBlueprintCost(const Blueprint& bp) const
     int total = 0;
     for (const BlueprintBuilding& bb : bp.buildings)
     {
-        for (const BuildingDef& def : m_config->buildings.buildings)
-        {
-            if (def.type == bb.type)
-            {
-                total += def.cost;
-                break;
-            }
-        }
+        const BuildingDef* def = m_config->buildings.findBuildingDef(bb.type);
+        if (def) { total += def->cost; }
     }
     return total;
 }
@@ -247,7 +177,7 @@ void BlueprintPanel::rebuildButtons()
     {
         const Blueprint& bp   = m_blueprints[static_cast<std::size_t>(i)];
         const int        cost = computeBlueprintCost(bp);
-        const QString label   = bp.name + "\n" + tr("%1 Blocks").arg(cost);
+        const QString label   = bp.name + "\n" + tr("%1 Building Blocks").arg(cost);
 
         QWidget*     row       = new QWidget(m_buttonsContainer);
         QHBoxLayout* rowLayout = new QHBoxLayout(row);
@@ -281,83 +211,42 @@ void BlueprintPanel::rebuildButtons()
     refreshButtonStates();
 }
 
-void BlueprintPanel::onSaveClicked()
+void BlueprintPanel::saveToDisk() const
 {
+    // Persist on shutdown; write errors are silently ignored (REQ-UI-BLUEPRINT-SAVE).
     const QString path = QCoreApplication::applicationDirPath() + "/blueprints.toml";
+    QFile file(path);
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) { return; }
     try
     {
         const std::string content = BlueprintSerializer::serialize(m_blueprints);
-        QFile file(path);
-        if (!file.open(QIODevice::WriteOnly | QIODevice::Text))
-        {
-            QMessageBox::critical(this, tr("Save Failed"),
-                tr("Could not open file for writing:\n%1").arg(path));
-            return;
-        }
         file.write(QByteArray::fromStdString(content));
     }
-    catch (const std::exception& e)
-    {
-        QMessageBox::critical(this, tr("Save Failed"),
-            tr("Failed to save blueprints:\n%1").arg(e.what()));
-    }
+    catch (...) {}
 }
 
-void BlueprintPanel::onLoadClicked()
+void BlueprintPanel::loadFromDisk()
 {
-    QMessageBox box(this);
-    box.setWindowTitle(tr("Load Blueprints"));
-    box.setText(tr("Load blueprints? This will replace all current blueprints."));
-    QPushButton* confirmBtn = box.addButton(tr("Confirm"), QMessageBox::AcceptRole);
-    box.addButton(tr("Cancel"), QMessageBox::RejectRole);
-    box.exec();
-    if (box.clickedButton() != confirmBtn) { return; }
-
+    // Load at startup (REQ-UI-BLUEPRINT-LOAD). Missing file: start empty, no error.
     const QString path = QCoreApplication::applicationDirPath() + "/blueprints.toml";
+    QFile file(path);
+    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) { return; }
     try
     {
-        QFile file(path);
-        if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
-        {
-            QMessageBox::critical(this, tr("Load Failed"),
-                tr("Could not open file:\n%1").arg(path));
-            return;
-        }
-        const std::string content = file.readAll().toStdString();
-        std::vector<Blueprint> loaded = BlueprintSerializer::deserialize(content);
-
-        if (m_activeIndex >= 0)
-        {
-            EventManager::getInstance()->sendEventImmediately(
-                std::make_shared<ExitBlueprintModeRequestedEvent>());
-            m_activeIndex = -1;
-        }
-
-        m_blueprints = std::move(loaded);
-        rebuildButtons();
+        m_blueprints = BlueprintSerializer::deserialize(file.readAll().toStdString());
     }
     catch (const std::exception& e)
     {
         QMessageBox::critical(this, tr("Load Failed"),
             tr("Failed to load blueprints:\n%1").arg(e.what()));
+        m_blueprints.clear();
     }
 }
 
 void BlueprintPanel::refreshButtonStates()
 {
-    const bool anyPlaceable = [&]() {
-        for (const BuildingId id : m_selectedBuildingIds)
-        {
-            const Building* b = m_sim->buildings().findBuilding(id);
-            if (!b) { continue; }
-            for (const BuildingDef& def : m_config->buildings.buildings)
-            {
-                if (def.type == b->type) { return def.playerPlaceable; }
-            }
-        }
-        return false;
-    }();
-    m_createBtn->setEnabled(anyPlaceable);
+    // A construction site counts the same as an operational building (REQ-UI-BLUEPRINT-CREATE).
+    m_createBtn->setEnabled(selectionHasPlaceableBuilding(*m_sim, m_selectedBuildingIds));
 
     for (int i = 0; i < static_cast<int>(m_blueprintButtons.size()); ++i)
     {
@@ -377,3 +266,17 @@ void BlueprintPanel::handleEvent(std::shared_ptr<const BlueprintModeExitedEvent>
 {
     clearActiveBlueprintButton();
 }
+
+void BlueprintPanel::handleEvent(std::shared_ptr<const TemporaryBlueprintRequestedEvent> /*event*/)
+{
+    // Temporary blueprint (REQ-UI-BLUEPRINT-TEMP): build from the current selection and
+    // enter placement mode without adding it to the list or persisting it. If nothing
+    // player-placeable is selected, do nothing.
+    Blueprint bp = createBlueprintFromSelection();
+    if (bp.buildings.empty()) { return; }
+
+    // No saved blueprint is active while a temporary one is being placed.
+    clearActiveBlueprintButton();
+    EventManager::getInstance()->sendEventImmediately(
+        std::make_shared<BlueprintPlacementRequestedEvent>(std::move(bp)));
+}

src/ui/BlueprintPanel.h

@@ -11,6 +11,7 @@
 #include "EventHandler.h"
 #include "GameConfig.h"
 #include "SelectionChangedEvent.h"
+#include "TemporaryBlueprintRequestedEvent.h"
 #include "Tick.h"
 
 class Simulation;
@@ -21,7 +22,8 @@ class QVBoxLayout;
 class BlueprintPanel : public QWidget,
                        public CombinedEventHandler<BuildingBlocksChangedEvent,
                                                    SelectionChangedEvent,
-                                                   BlueprintModeExitedEvent>
+                                                   BlueprintModeExitedEvent,
+                                                   TemporaryBlueprintRequestedEvent>
 {
     Q_OBJECT
 
@@ -33,13 +35,12 @@ private:
     void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const SelectionChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const BlueprintModeExitedEvent> event) override;
+    void handleEvent(std::shared_ptr<const TemporaryBlueprintRequestedEvent> event) override;
 
 private slots:
     void onCreateClicked();
     void onDeleteBlueprintClicked(int index);
     void onBlueprintButtonClicked(int index);
-    void onSaveClicked();
-    void onLoadClicked();
 
 private:
     void onSelectionChanged(const std::vector<BuildingId>& ids);
@@ -48,6 +49,8 @@ private:
     int       computeBlueprintCost(const Blueprint& bp) const;
     void      rebuildButtons();
     void      refreshButtonStates();
+    void      loadFromDisk();
+    void      saveToDisk() const;
 
     Simulation*               m_sim;
     const GameConfig*         m_config;
@@ -57,8 +60,6 @@ private:
     std::vector<Blueprint>    m_blueprints;
     std::vector<QPushButton*> m_blueprintButtons;
     QPushButton*              m_createBtn;
-    QPushButton*              m_saveBtn;
-    QPushButton*              m_loadBtn;
     QWidget*                  m_buttonsContainer;
     QVBoxLayout*              m_buttonsLayout;
 };

src/ui/BuildButtonGrid.cpp

@@ -38,10 +38,14 @@ BuildButtonGrid::BuildButtonGrid(const GameConfig* config, QWidget* parent)
         m_costs[def.type] = def.cost;
 
         const QString label = QString::fromStdString(toDisplayName(def.id))
-            + "\n" + tr("%1 Blocks").arg(def.cost);
+            + "\n" + tr("%1 Building Blocks").arg(def.cost);
         QPushButton* btn = new QPushButton(label, this);
         btn->setCheckable(true);
         btn->setFixedHeight(48);
+        if (def.tooltip)
+        {
+            btn->setToolTip(QString::fromStdString(*def.tooltip));
+        }
         layout->addWidget(btn, row, col);
 
         const int idx = static_cast<int>(m_buttons.size());

src/ui/CMakeLists.txt

@@ -3,6 +3,7 @@ SET(HDRS
     ${CMAKE_CURRENT_SOURCE_DIR}/VisualsConfig.h
     ${CMAKE_CURRENT_SOURCE_DIR}/VisualsLoader.h
     ${CMAKE_CURRENT_SOURCE_DIR}/MainWindow.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/ModalDimOverlay.h
     ${CMAKE_CURRENT_SOURCE_DIR}/GameWorldView.h
     ${CMAKE_CURRENT_SOURCE_DIR}/HeaderBar.h
     ${CMAKE_CURRENT_SOURCE_DIR}/BuildButtonGrid.h
@@ -13,6 +14,7 @@ SET(HDRS
     ${CMAKE_CURRENT_SOURCE_DIR}/ShipStatsPanel.h
     ${CMAKE_CURRENT_SOURCE_DIR}/SchematicChoiceDialog.h
     ${CMAKE_CURRENT_SOURCE_DIR}/RecipeSelectionDialog.h
+    ${CMAKE_CURRENT_SOURCE_DIR}/RecipeTooltip.h
     PARENT_SCOPE
 )
 
@@ -20,6 +22,7 @@ SET(SRCS
     ${SRCS}
     ${CMAKE_CURRENT_SOURCE_DIR}/VisualsLoader.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/MainWindow.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/ModalDimOverlay.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/GameWorldView.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/HeaderBar.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/BuildButtonGrid.cpp
@@ -30,5 +33,6 @@ SET(SRCS
     ${CMAKE_CURRENT_SOURCE_DIR}/ShipStatsPanel.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/SchematicChoiceDialog.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/RecipeSelectionDialog.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/RecipeTooltip.cpp
     PARENT_SCOPE
 )

src/ui/GameWorldView.h

@@ -14,6 +14,7 @@
 #include <QVector2D>
 
 #include "Blueprint.h"
+#include "BuildingConfig.h"
 #include "BlueprintModeExitedEvent.h"
 #include "BlueprintPlacementRequestedEvent.h"
 #include "BuilderModeExitedEvent.h"
@@ -114,11 +115,16 @@ private:
     bool canAfford(BuildingType type) const;
 
     void drawTiles(QPainter& painter);
+    void drawPortItems(QPainter& painter);
     void drawBuildings(QPainter& painter);
+    void drawSelectionHighlights(QPainter& painter);
+    void drawCopyConfigFeedback(QPainter& painter);
     void drawStations(QPainter& painter);
     void drawBeltItems(QPainter& painter);
     void drawScrap(QPainter& painter);
     void drawShips(QPainter& painter);
+    void drawHpBar(QPainter& painter, qreal left, qreal top, qreal width,
+                   float fraction, bool isEnemy);
     void drawDebugSensorRanges(QPainter& painter);
     void drawDebugTargetLines(QPainter& painter);
     void drawDebugOverlay(QPainter& painter);
@@ -129,20 +135,32 @@ private:
 
     float    tilePx() const;
     float    viewportWidthTiles() const;
+    // World-X (tiles) at the left edge of the viewport. m_scrollXTiles stores the
+    // view center; this derives the left edge the world<->widget conversions need.
+    float    viewLeftTiles() const;
     QPointF  worldToWidget(QVector2D worldPos) const;
     QPointF  tileToWidget(QPoint tile) const;
     QPoint   widgetToTile(QPoint widgetPt) const;
     QRectF   tileRect(QPoint tile) const;
     QRect    viewportRect() const;
+    // Widget-space rectangle covering a building or construction site's footprint,
+    // or nullopt if the id resolves to neither. Shared by the selection highlight
+    // and the copy-settings feedback (REQ-BLD-COPY-CONFIG-FEEDBACK).
+    std::optional<QRectF> footprintWidgetRect(BuildingId id) const;
 
     float    asteroidLeftEdge() const;
     float    enemyStationRightEdge() const;
+    // Horizontal pan speed at a given view-center X, in tiles/s (REQ-UI-SCROLL-SPEED).
+    float    panSpeedTilesPerSecondAt(float viewCenterXTiles) const;
     void     clampScroll();
 
     bool     isValidPlacement(BuildingType type, QPoint anchor, Rotation rot) const;
     const BuildingDef* findBuildingDef(BuildingType type) const;
     BuildingId buildingAtTile(QPoint tile) const;
     BuildingId siteAtTile(QPoint tile) const;
+    // Ids of all buildings and construction sites whose footprint intersects
+    // the tile box spanned by the two (unordered) corner tiles.
+    std::vector<BuildingId> buildingsInBox(QPoint cornerA, QPoint cornerB) const;
     QVector2D  widgetToWorld(QPoint widgetPt) const;
 
     void     drawPortGlyph(QPainter& painter, QPoint bodyTile,
@@ -154,9 +172,22 @@ private:
     void     placeBlueprintAtTile(QPoint center);
 
     std::optional<QVector2D> entityPosition(entt::entity entity) const;
+    // Clears the scrap selection, emitting an empty ScrapSelectionChangedEvent when
+    // it was non-empty (REQ-UI-SCRAP-CLICK-SELECT). Used when another selection
+    // category takes over.
+    void                     clearScrapSelection();
+    // Drops despawned or fully-collected piles from the scrap selection and re-emits
+    // when it changed (REQ-UI-SCRAP-CLICK-SELECT). Called each frame from onFrame().
+    void                     pruneDespawnedScrap();
     void                     stepSpeed(int delta);
     void                     placeAtTile(QPoint tile);
 
+    // Copy-settings gesture (REQ-BLD-COPY-CONFIG): Shift+right-click copies a
+    // building's configuration into m_copiedConfig; Shift+left-click applies it to
+    // another building of the same type via the existing configuration commands.
+    void     copyConfigFrom(BuildingId id);
+    void     pasteConfigTo(BuildingId id);
+
     void     enterBuilderMode(BuildingType type);
     void     exitBuilderMode();
     void     enterBlueprintMode(Blueprint blueprint);
@@ -173,7 +204,6 @@ private:
     // Beam lifetime in game ticks so beams freeze with the simulation when
     // paused or slowed, instead of fading on wall-clock time (REQ-SHP-FIRING-BEAM).
     static constexpr Tick    kBeamLifetimeTicks      = secondsToTicks(0.3);
-    static constexpr float   kScrollSpeedTilesPerSec = 10.0f;
 
     Simulation*          m_sim;
     const GameConfig*    m_config;
@@ -192,6 +222,7 @@ private:
     std::mt19937  m_rng;
     double        m_gameSpeedMultiplier;
     double        m_prevNonZeroSpeed;
+    // World-X (tiles) at the center of the viewport (see viewLeftTiles()).
     float         m_scrollXTiles;
 
     QTimer* m_renderTimer;
@@ -208,12 +239,29 @@ private:
     std::optional<Blueprint> m_blueprintMode;
     QPoint                   m_blueprintGhostTile;
 
+    // Temporary cache for the copy-settings gesture (REQ-BLD-COPY-CONFIG); held
+    // only while Shift is down and cleared on Shift release.
+    std::optional<BuildingConfig> m_copiedConfig;
+
+    // Brief outline flash shown on a building when settings are copied from it or
+    // pasted onto it (REQ-BLD-COPY-CONFIG-FEEDBACK). remainingMs counts down in
+    // wall-clock time so the flash plays at a fixed length regardless of game speed
+    // (and while paused).
+    struct CopyConfigFlash
+    {
+        BuildingId id;
+        qint64     remainingMs;
+    };
+    std::vector<CopyConfigFlash> m_copyConfigFlashes;
+    static constexpr qint64      kCopyFlashDurationMs = 300;
+
     bool     m_demolishMode;
     BuildingId m_demolishHoverBuildingId;
     bool     m_debugDraw;
 
     std::vector<BuildingId> m_selectedBuildingIds;
     std::optional<entt::entity> m_selectedEntity;
+    std::vector<entt::entity> m_selectedScrap;
     bool                  m_boxSelecting;
     QPoint                m_boxStartTile;
     QPoint                m_boxCurrentTile;
@@ -226,6 +274,7 @@ private:
 
     Tick m_lastTick          = Tick(-1);
     int  m_lastBlocks        = -1;
+    int  m_lastExpansionCost = -1;
     int  m_lastBossCounter   = -1;
     Tick m_lastBossCountdown = Tick(-1);
     int  m_lastArtifactCount = -1;

src/ui/HeaderBar.cpp

@@ -8,6 +8,8 @@
 #include <QPushButton>
 #include <QSignalMapper>
 
+#include "Command.h"
+#include "CommandRequestedEvent.h"
 #include "EventManager.h"
 #include "SpeedChangeRequestedEvent.h"
 #include "Tick.h"
@@ -15,7 +17,7 @@
 const double HeaderBar::kSpeeds[]   = { 0.0, 0.5, 1.0, 2.0, 10.0 };
 const int    HeaderBar::kSpeedCount = 5;
 
-HeaderBar::HeaderBar(QWidget* parent)
+HeaderBar::HeaderBar(const GameConfig* config, QWidget* parent)
     : QWidget(parent)
 {
     QHBoxLayout* layout = new QHBoxLayout(this);
@@ -23,7 +25,12 @@ HeaderBar::HeaderBar(QWidget* parent)
     layout->setSpacing(8);
 
     m_timeLabel      = new QLabel("00:00", this);
-    m_blocksLabel    = new QLabel(tr("Blocks: 0"), this);
+    m_blocksLabel    = new QLabel(tr("Building Blocks: 0"), this);
+    if (config->world.buildingBlocksTooltip)
+    {
+        m_blocksLabel->setToolTip(
+            QString::fromStdString(*config->world.buildingBlocksTooltip));
+    }
     m_artifactsLabel = new QLabel(tr("Artifacts: 0/?"), this);
     m_bossLabel      = new QLabel(tr("Boss Wave #1  Next boss: 5:00"), this);
     layout->addWidget(m_timeLabel);
@@ -32,6 +39,17 @@ HeaderBar::HeaderBar(QWidget* parent)
     layout->addStretch();
     layout->addWidget(m_bossLabel);
 
+    // Asteroid expansion button, to the left of the speed buttons (REQ-UI-HEADER,
+    // REQ-UI-EXPAND-BUTTON). Caption/enabled state are set on the first
+    // ExpansionCostChangedEvent; clicking requests an ExpandAsteroidCommand.
+    m_expandButton = new QPushButton(tr("Expand"), this);
+    layout->addWidget(m_expandButton);
+    connect(m_expandButton, &QPushButton::clicked, this, []() {
+        EventManager::getInstance()->sendEventImmediately(
+            std::make_shared<CommandRequestedEvent>(
+                std::make_shared<ExpandAsteroidCommand>()));
+    });
+
     const char* labels[] = { "0x", "0.5x", "1x", "2x", "10x" };
     QSignalMapper* mapper = new QSignalMapper(this);
     for (int i = 0; i < kSpeedCount; ++i)
@@ -67,7 +85,21 @@ void HeaderBar::handleEvent(std::shared_ptr<const TickAdvancedEvent> event)
 
 void HeaderBar::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
 {
-    m_blocksLabel->setText(tr("Blocks: %1").arg(event->blocks));
+    m_blocks = event->blocks;
+    m_blocksLabel->setText(tr("Building Blocks: %1").arg(event->blocks));
+    updateExpandButton();
+}
+
+void HeaderBar::handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> event)
+{
+    m_expansionCost = event->cost;
+    updateExpandButton();
+}
+
+void HeaderBar::updateExpandButton()
+{
+    m_expandButton->setText(tr("Expand: %1 Building Blocks").arg(m_expansionCost));
+    m_expandButton->setEnabled(m_blocks >= m_expansionCost);
 }
 
 void HeaderBar::handleEvent(std::shared_ptr<const GameSpeedChangedEvent> event)

src/ui/HeaderBar.h

@@ -8,6 +8,8 @@
 #include "BossWaveUpdatedEvent.h"
 #include "BuildingBlocksChangedEvent.h"
 #include "EventHandler.h"
+#include "ExpansionCostChangedEvent.h"
+#include "GameConfig.h"
 #include "GameSpeedChangedEvent.h"
 #include "Tick.h"
 #include "TickAdvancedEvent.h"
@@ -18,6 +20,7 @@ class QPushButton;
 class HeaderBar : public QWidget,
                   public CombinedEventHandler<TickAdvancedEvent,
                                               BuildingBlocksChangedEvent,
+                                              ExpansionCostChangedEvent,
                                               GameSpeedChangedEvent,
                                               BossWaveUpdatedEvent,
                                               ArtifactCountChangedEvent>
@@ -25,7 +28,7 @@ class HeaderBar : public QWidget,
     Q_OBJECT
 
 public:
-    explicit HeaderBar(QWidget* parent = nullptr);
+    explicit HeaderBar(const GameConfig* config, QWidget* parent = nullptr);
     ~HeaderBar() override;
 
 private slots:
@@ -34,16 +37,25 @@ private slots:
 private:
     void handleEvent(std::shared_ptr<const TickAdvancedEvent> event) override;
     void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;
+    void handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const GameSpeedChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const BossWaveUpdatedEvent> event) override;
     void handleEvent(std::shared_ptr<const ArtifactCountChangedEvent> event) override;
 
+    // Refreshes the Expand button caption and enabled state from the current
+    // expansion cost and building block stock (REQ-UI-EXPAND-BUTTON).
+    void updateExpandButton();
+
     QLabel*                  m_timeLabel;
     QLabel*                  m_blocksLabel;
     QLabel*                  m_artifactsLabel;
     QLabel*                  m_bossLabel;
+    QPushButton*             m_expandButton;
     std::vector<QPushButton*> m_speedButtons;
 
+    int                      m_blocks        = 0;
+    int                      m_expansionCost = 0;
+
     static const double kSpeeds[];
     static const int    kSpeedCount;
 };

src/ui/MainWindow.cpp

@@ -42,15 +42,15 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir,
     setWindowTitle(tr("Dota Factory"));
     resize(1280, 768);
 
-    m_headerBar = new HeaderBar(this);
+    m_headerBar = new HeaderBar(&sim->config(), this);
 
     m_gameWorldView = new GameWorldView(sim, &sim->config(), &m_visuals, m_configDir,
                                         m_replay.get(), this);
 
     m_sidePanel = new QWidget(this);
     QVBoxLayout* sideLayout = new QVBoxLayout(m_sidePanel);
-    sideLayout->setContentsMargins(0, 0, 0, 0);
-    sideLayout->setSpacing(0);
+    sideLayout->setContentsMargins(1, 1, 1, 1);
+    sideLayout->setSpacing(1);
 
     m_selectedBuildingPanel = new SelectedBuildingPanel(sim, &sim->config(), m_sidePanel);
     m_buildButtonGrid       = new BuildButtonGrid(&sim->config(), m_sidePanel);
@@ -60,6 +60,24 @@ MainWindow::MainWindow(Simulation* sim, const std::string& configDir,
     sideLayout->addWidget(m_buildButtonGrid,       1);
     sideLayout->addWidget(m_blueprintPanel,        1);
 
+    // Draw a thin border around each of the three side-panel sections. The class
+    // scoped selectors keep the border on the panels themselves rather than
+    // cascading onto their child widgets; WA_StyledBackground lets the plain
+    // QWidget subclasses honor the stylesheet box (border/background).
+    for (QWidget* panel : { static_cast<QWidget*>(m_selectedBuildingPanel),
+                            static_cast<QWidget*>(m_buildButtonGrid),
+                            static_cast<QWidget*>(m_blueprintPanel) })
+    {
+        panel->setAttribute(Qt::WA_StyledBackground, true);
+    }
+    m_sidePanel->setStyleSheet(QStringLiteral(
+        "SelectedBuildingPanel, BuildButtonGrid, BlueprintPanel {"
+        " border: 1px solid palette(mid); }"));
+
+    // Created last so it stacks above the other children; covers the whole window and
+    // dims the game behind modal dialogs/menus (REQ-UI-MODAL-DIM).
+    m_dimOverlay = new ModalDimOverlay(m_visuals.overlays.modalDim, this);
+
     m_gameWorldView->setFocus();
 
     connect(qApp, &QApplication::focusChanged, this, [this](QWidget*, QWidget* newWidget) {
@@ -130,6 +148,7 @@ void MainWindow::layoutPanels()
     m_headerBar->setGeometry(0, 0, mainW, headerH);
     m_gameWorldView->setGeometry(0, headerH, mainW, totalH - headerH);
     m_sidePanel->setGeometry(mainW, 0, sideW, totalH);
+    m_dimOverlay->setGeometry(0, 0, totalW, totalH);
 }
 
 void MainWindow::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
@@ -142,7 +161,8 @@ void MainWindow::handleEvent(std::shared_ptr<const SchematicChoicesAvailableEven
     const double prevSpeed = m_gameWorldView->gameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
-    SchematicChoiceDialog dialog(event->choices, this);
+    ModalDimScope dim(*m_dimOverlay);
+    SchematicChoiceDialog dialog(event->choices, m_sim->config().recipes, this);
     dialog.exec();
 
     std::shared_ptr<ApplySchematicChoiceCommand> command =
@@ -160,6 +180,7 @@ void MainWindow::handleEvent(std::shared_ptr<const EscapeMenuRequestedEvent> /*e
     const double prevSpeed = m_gameWorldView->gameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
+    ModalDimScope dim(*m_dimOverlay);
     QMessageBox box(this);
     box.setWindowTitle(tr("Paused"));
     QPushButton* continueBtn = box.addButton(tr("Continue"), QMessageBox::AcceptRole);
@@ -178,6 +199,7 @@ void MainWindow::handleEvent(std::shared_ptr<const EscapeMenuRequestedEvent> /*e
                 ConfigLoader::loadFromDirectory(m_configDir));
             VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
             m_visuals = std::move(newVisuals);
+            m_dimOverlay->setDimColor(m_visuals.overlays.modalDim);
         }
         catch (const std::exception& e)
         {
@@ -206,11 +228,44 @@ void MainWindow::handleEvent(std::shared_ptr<const EscapeMenuRequestedEvent> /*e
     }
 }
 
-void MainWindow::handleEvent(std::shared_ptr<const LayoutDialogRequestedEvent> event)
+void MainWindow::openShipLayoutDialog(BuildingId shipyardId,
+                                      const std::string& schematicId,
+                                      const ShipLayoutConfig& currentLayout)
 {
     const double prevSpeed = m_gameWorldView->gameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
+    std::set<std::string> unlockedModuleIds;
+    for (const ModuleDef& def : m_sim->config().modules.modules)
+    {
+        if (m_sim->isModuleSchematicUnlocked(def.id))
+        {
+            unlockedModuleIds.insert(def.id);
+        }
+    }
+
+    ModalDimScope dim(*m_dimOverlay);
+    ShipLayoutDialog dialog(&m_sim->config(), schematicId, currentLayout,
+                            m_layoutBlueprints,
+                            std::move(unlockedModuleIds),
+                            m_gameWorldView->isDebugDrawEnabled(),
+                            this);
+    if (dialog.exec() == QDialog::Accepted && dialog.result().has_value())
+    {
+        std::shared_ptr<SetShipLayoutCommand> command =
+            std::make_shared<SetShipLayoutCommand>();
+        command->id     = shipyardId;
+        command->layout = *dialog.result();
+        EventManager::getInstance()->sendEventImmediately(
+            std::make_shared<CommandRequestedEvent>(command));
+    }
+
+    m_gameWorldView->setGameSpeed(prevSpeed);
+    m_gameWorldView->resetFrameTimer();
+}
+
+void MainWindow::handleEvent(std::shared_ptr<const LayoutDialogRequestedEvent> event)
+{
     // A construction site has no Building yet; fall back to its site record so
     // the shipyard layout can be configured before it is built (REQ-BLD-SITE-CONFIG).
     const Building* b = m_sim->buildings().findBuilding(event->shipyardId);
@@ -218,8 +273,6 @@ void MainWindow::handleEvent(std::shared_ptr<const LayoutDialogRequestedEvent> e
         b ? nullptr : m_sim->buildings().findSite(event->shipyardId);
     if (!b && !s)
     {
-        m_gameWorldView->setGameSpeed(prevSpeed);
-        m_gameWorldView->resetFrameTimer();
         return;
     }
 
@@ -233,32 +286,7 @@ void MainWindow::handleEvent(std::shared_ptr<const LayoutDialogRequestedEvent> e
         currentLayout = *layoutOpt;
     }
 
-    std::set<std::string> unlockedModuleIds;
-    for (const ModuleDef& def : m_sim->config().modules.modules)
-    {
-        if (m_sim->isModuleSchematicUnlocked(def.id))
-        {
-            unlockedModuleIds.insert(def.id);
-        }
-    }
-
-    ShipLayoutDialog dialog(&m_sim->config(), schematicId, currentLayout,
-                            m_layoutBlueprints,
-                            std::move(unlockedModuleIds),
-                            m_gameWorldView->isDebugDrawEnabled(),
-                            this);
-    if (dialog.exec() == QDialog::Accepted && dialog.result().has_value())
-    {
-        std::shared_ptr<SetShipLayoutCommand> command =
-            std::make_shared<SetShipLayoutCommand>();
-        command->id     = event->shipyardId;
-        command->layout = *dialog.result();
-        EventManager::getInstance()->sendEventImmediately(
-            std::make_shared<CommandRequestedEvent>(command));
-    }
-
-    m_gameWorldView->setGameSpeed(prevSpeed);
-    m_gameWorldView->resetFrameTimer();
+    openShipLayoutDialog(event->shipyardId, schematicId, currentLayout);
 }
 
 void MainWindow::handleEvent(std::shared_ptr<const RecipeSelectionRequestedEvent> event)
@@ -278,13 +306,23 @@ void MainWindow::handleEvent(std::shared_ptr<const RecipeSelectionRequestedEvent
         return;
     }
 
+    // Held across both the selection dialog and any auto-opened layout dialog so the
+    // dim stays continuously visible through that sequence (REQ-UI-MODAL-DIM).
+    ModalDimScope dim(*m_dimOverlay);
+
     const BuildingType type = b ? b->type : s->type;
+    // Captured as a copy: a queued command may drain during the modal dialog's
+    // event loop and reallocate the building vectors, so b/s must not be
+    // dereferenced after dialog.exec() returns.
+    const std::string oldSchematic = b ? b->recipeId : s->recipeId;
     const std::vector<RecipeSelectionOption> options =
         buildRecipeSelectionOptions(type, *m_sim, m_sim->config());
     const QString title = (type == BuildingType::Shipyard)
         ? tr("Select Schematic")
         : tr("Select Recipe");
 
+    bool autoOpenLayout = false;
+    std::string chosenSchematic;
     RecipeSelectionDialog dialog(options, title, this);
     if (dialog.exec() == QDialog::Accepted && dialog.getChosenId().has_value())
     {
@@ -293,10 +331,27 @@ void MainWindow::handleEvent(std::shared_ptr<const RecipeSelectionRequestedEvent
         command->recipeId = *dialog.getChosenId();
         EventManager::getInstance()->sendEventImmediately(
             std::make_shared<CommandRequestedEvent>(command));
+
+        // REQ-MOD-UI-AUTO-DIALOG: picking a new schematic for a shipyard opens the
+        // layout configuration dialog immediately. Only on an actual change.
+        if (type == BuildingType::Shipyard && *dialog.getChosenId() != oldSchematic)
+        {
+            autoOpenLayout = true;
+            chosenSchematic = *dialog.getChosenId();
+        }
     }
 
     m_gameWorldView->setGameSpeed(prevSpeed);
     m_gameWorldView->resetFrameTimer();
+
+    // The SetRecipeCommand above is queued (drains on a later frame) and clears
+    // the shipyard's layout, so open the dialog with the chosen schematic and an
+    // empty layout rather than reading the not-yet-updated building state. Speed
+    // is already restored so the helper snapshots the real speed to restore.
+    if (autoOpenLayout)
+    {
+        openShipLayoutDialog(event->buildingId, chosenSchematic, ShipLayoutConfig{});
+    }
 }
 
 void MainWindow::handleEvent(std::shared_ptr<const GameOverEvent> /*event*/)
@@ -306,6 +361,7 @@ void MainWindow::handleEvent(std::shared_ptr<const GameOverEvent> /*event*/)
     const int minutes = totalSeconds / 60;
     const int seconds = totalSeconds % 60;
 
+    ModalDimScope dim(*m_dimOverlay);
     QMessageBox box(this);
     box.setWindowTitle(tr("Game Over"));
     box.setText(tr("HQ destroyed!\nSurvival time: %1:%2")
@@ -324,6 +380,7 @@ void MainWindow::handleEvent(std::shared_ptr<const GameOverEvent> /*event*/)
                 ConfigLoader::loadFromDirectory(m_configDir));
             VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
             m_visuals = std::move(newVisuals);
+            m_dimOverlay->setDimColor(m_visuals.overlays.modalDim);
         }
         catch (const std::exception& e)
         {
@@ -351,6 +408,7 @@ void MainWindow::handleEvent(std::shared_ptr<const WinEvent> /*event*/)
     const int minutes = totalSeconds / 60;
     const int seconds = totalSeconds % 60;
 
+    ModalDimScope dim(*m_dimOverlay);
     QMessageBox box(this);
     box.setWindowTitle(tr("Won!"));
     box.setText(tr("You collected all artifacts!\nSurvival time: %1:%2")
@@ -367,6 +425,7 @@ void MainWindow::handleEvent(std::shared_ptr<const WinEvent> /*event*/)
             GameConfig newConfig = ConfigLoader::loadFromDirectory(m_configDir);
             VisualsConfig newVisuals = VisualsLoader::load(m_configDir + "/visuals.toml");
             m_visuals = std::move(newVisuals);
+            m_dimOverlay->setDimColor(m_visuals.overlays.modalDim);
             m_sim->reset(std::move(newConfig));
         }
         catch (const std::exception& e)

src/ui/MainWindow.h

@@ -12,9 +12,11 @@
 #include "EventHandler.h"
 #include "GameOverEvent.h"
 #include "LayoutDialogRequestedEvent.h"
+#include "ModalDimOverlay.h"
 #include "WinEvent.h"
 #include "RecipeSelectionRequestedEvent.h"
 #include "SchematicChoicesAvailableEvent.h"
+#include "ShipLayout.h"
 #include "ShipLayoutBlueprint.h"
 #include "Tick.h"
 #include "VisualsConfig.h"
@@ -57,6 +59,12 @@ private:
     void handleEvent(std::shared_ptr<const EscapeMenuRequestedEvent> event) override;
     void handleEvent(std::shared_ptr<const LayoutDialogRequestedEvent> event) override;
     void handleEvent(std::shared_ptr<const RecipeSelectionRequestedEvent> event) override;
+
+    // Opens the shipyard layout configuration dialog for the given schematic and
+    // current layout, applying the result via SetShipLayoutCommand (REQ-MOD-UI-DIALOG).
+    void openShipLayoutDialog(BuildingId shipyardId,
+                              const std::string& schematicId,
+                              const ShipLayoutConfig& currentLayout);
     void layoutPanels();
 
 private:
@@ -69,6 +77,7 @@ private:
     BuildButtonGrid*       m_buildButtonGrid;
     BlueprintPanel*        m_blueprintPanel;
     QWidget*               m_sidePanel;
+    ModalDimOverlay*       m_dimOverlay = nullptr;
 
     std::vector<ShipLayoutBlueprint> m_layoutBlueprints;
     std::shared_ptr<ParsedReplay>    m_replay;  // non-null => view-only playback

src/ui/ModalDimOverlay.cpp

@@ -0,0 +1,46 @@
+#include "ModalDimOverlay.h"
+
+#include <QPainter>
+
+ModalDimOverlay::ModalDimOverlay(const QColor& dimColor, QWidget* parent)
+    : QWidget(parent)
+    , m_dimColor(dimColor)
+{
+    setAttribute(Qt::WA_TransparentForMouseEvents, true);
+    hide();
+}
+
+void ModalDimOverlay::pushModal()
+{
+    if (m_modalDepth++ == 0)
+    {
+        raise();
+        show();
+        // Force an immediate synchronous paint so the scrim is visible before the
+        // caller enters a blocking dialog exec() (no undimmed frame flashes through).
+        repaint();
+    }
+}
+
+void ModalDimOverlay::popModal()
+{
+    if (m_modalDepth > 0 && --m_modalDepth == 0)
+    {
+        hide();
+    }
+}
+
+void ModalDimOverlay::setDimColor(const QColor& dimColor)
+{
+    m_dimColor = dimColor;
+    if (isVisible())
+    {
+        update();
+    }
+}
+
+void ModalDimOverlay::paintEvent(QPaintEvent* /*event*/)
+{
+    QPainter painter(this);
+    painter.fillRect(rect(), m_dimColor);
+}

src/ui/ModalDimOverlay.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include <QColor>
+#include <QWidget>
+
+class QPaintEvent;
+
+// A window-wide, semi-transparent scrim drawn over the entire game window while a
+// modal dialog or menu is open, behind that modal (REQ-UI-MODAL-DIM). It is a child
+// of the main window covering its full rect and is transparent to mouse events, so it
+// only dims the game presentation and never intercepts input.
+//
+// Visibility is reference-counted via pushModal()/popModal() so that a single dim is
+// shown across nested or back-to-back modals (e.g. the recipe selection dialog that
+// immediately opens the layout dialog) rather than flickering or stacking overlays.
+class ModalDimOverlay : public QWidget
+{
+    Q_OBJECT
+
+public:
+    ModalDimOverlay(const QColor& dimColor, QWidget* parent);
+
+    // Raise + show on the first active modal; hide when the last one closes.
+    void pushModal();
+    void popModal();
+
+    // Update the dim color (e.g. after a config reload on Restart, REQ-CFG-RELOAD).
+    void setDimColor(const QColor& dimColor);
+
+protected:
+    void paintEvent(QPaintEvent* event) override;
+
+private:
+    QColor m_dimColor;
+    int    m_modalDepth = 0;
+};
+
+// RAII guard: shows the dim overlay for the duration of a scope (typically around a
+// blocking dialog exec()) and hides it (via reference count) on scope exit.
+class ModalDimScope
+{
+public:
+    explicit ModalDimScope(ModalDimOverlay& overlay)
+        : m_overlay(overlay)
+    {
+        m_overlay.pushModal();
+    }
+
+    ~ModalDimScope()
+    {
+        m_overlay.popModal();
+    }
+
+    ModalDimScope(const ModalDimScope&) = delete;
+    ModalDimScope& operator=(const ModalDimScope&) = delete;
+
+private:
+    ModalDimOverlay& m_overlay;
+};

src/ui/RecipeSelectionDialog.cpp

@@ -12,6 +12,7 @@
 #include "DisplayName.h"
 #include "GameConfig.h"
 #include "RecipesConfig.h"
+#include "RecipeTooltip.h"
 #include "ShipsConfig.h"
 #include "Simulation.h"
 
@@ -22,40 +23,7 @@ QString itemLine(const std::string& itemId, int amount)
 {
     return QStringLiteral("  ")
         + QString::fromStdString(toDisplayName(itemId))
-        + QStringLiteral(" ×") + QString::number(amount);
-}
-
-QString recipeTooltip(const RecipeDef& recipe)
-{
-    QStringList lines;
-    lines << QObject::tr("Recipe: %1")
-        .arg(QString::fromStdString(toDisplayName(recipe.id)));
-
-    if (recipe.inputs.empty())
-    {
-        lines << QObject::tr("Inputs: none");
-    }
-    else
-    {
-        lines << QObject::tr("Inputs:");
-        for (const RecipeIngredient& ingredient : recipe.inputs)
-        {
-            lines << itemLine(ingredient.item, ingredient.amount);
-        }
-    }
-
-    lines << QObject::tr("Completion time: %1 s").arg(recipe.durationSeconds);
-
-    if (!recipe.outputs.empty())
-    {
-        lines << QObject::tr("Produces:");
-        for (const RecipeOutput& output : recipe.outputs)
-        {
-            lines << itemLine(output.item, output.amount);
-        }
-    }
-
-    return lines.join('\n');
+        + QStringLiteral(" x ") + QString::number(amount);
 }
 
 QString shipTooltip(const ShipDef& def)
@@ -76,6 +44,7 @@ QString shipTooltip(const ShipDef& def)
         {
             lines << itemLine(material.item, material.amount);
         }
+        lines << QObject::tr("  + installed modules");
     }
 
     lines << QObject::tr("Completion time: %1 s")
@@ -116,7 +85,7 @@ std::vector<RecipeSelectionOption> buildRecipeSelectionOptions(
             }
             options.push_back({recipe.id,
                                QString::fromStdString(toDisplayName(recipe.id)),
-                               recipeTooltip(recipe)});
+                               buildRecipeTooltip(recipe)});
         }
     }
 

src/ui/RecipeTooltip.cpp

@@ -0,0 +1,52 @@
+#include "RecipeTooltip.h"
+
+#include <QObject>
+#include <QStringList>
+
+#include "DisplayName.h"
+#include "RecipesConfig.h"
+
+namespace
+{
+
+QString itemLine(const std::string& itemId, int amount)
+{
+    return QStringLiteral("  ")
+        + QString::fromStdString(toDisplayName(itemId))
+        + QStringLiteral(" x ") + QString::number(amount);
+}
+
+}  // namespace
+
+QString buildRecipeTooltip(const RecipeDef& recipe)
+{
+    QStringList lines;
+    lines << QObject::tr("Recipe: %1")
+        .arg(QString::fromStdString(toDisplayName(recipe.id)));
+
+    if (recipe.inputs.empty())
+    {
+        lines << QObject::tr("Inputs: none");
+    }
+    else
+    {
+        lines << QObject::tr("Inputs:");
+        for (const RecipeIngredient& ingredient : recipe.inputs)
+        {
+            lines << itemLine(ingredient.item, ingredient.amount);
+        }
+    }
+
+    lines << QObject::tr("Completion time: %1 s").arg(recipe.durationSeconds);
+
+    if (!recipe.outputs.empty())
+    {
+        lines << QObject::tr("Produces:");
+        for (const RecipeOutput& output : recipe.outputs)
+        {
+            lines << itemLine(output.item, output.amount);
+        }
+    }
+
+    return lines.join('\n');
+}

src/ui/RecipeTooltip.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <QString>
+
+struct RecipeDef;
+
+// Builds the recipe info tooltip text (REQ-UI-SELECT-TOOLTIP): the recipe name,
+// each input item name and quantity, the completion time, and the produced
+// output item name and quantity. Shared by the recipe-selection dialog and the
+// schematic choice dialog's "Unlocks recipes:" list so both render identically.
+QString buildRecipeTooltip(const RecipeDef& recipe);

src/ui/SchematicChoiceDialog.cpp

@@ -3,11 +3,29 @@
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QPushButton>
-#include <QStringList>
 #include <QVBoxLayout>
 
+#include "DisplayName.h"
+#include "RecipeTooltip.h"
+#include "RecipesConfig.h"
+
+namespace
+{
+
+const RecipeDef* findRecipe(const RecipesConfig& recipes, const std::string& id)
+{
+    for (const RecipeDef& recipe : recipes.recipes)
+    {
+        if (recipe.id == id) { return &recipe; }
+    }
+    return nullptr;
+}
+
+}  // namespace
+
 SchematicChoiceDialog::SchematicChoiceDialog(
     const std::vector<SchematicChoiceOption>& options,
+    const RecipesConfig& recipes,
     QWidget* parent)
     : QDialog(parent)
     , m_chosenIndex(0)
@@ -70,30 +88,33 @@ SchematicChoiceDialog::SchematicChoiceDialog(
             typeLabel->setAlignment(Qt::AlignCenter);
             cardLayout->addWidget(typeLabel);
 
-            QLabel* unlocksHeaderLabel = new QLabel(tr("Unlocks recipes for:"), card);
+            QLabel* unlocksHeaderLabel = new QLabel(tr("Unlocks recipes:"), card);
             QFont unlocksHeaderFont = unlocksHeaderLabel->font();
             unlocksHeaderFont.setBold(true);
             unlocksHeaderLabel->setFont(unlocksHeaderFont);
             unlocksHeaderLabel->setAlignment(Qt::AlignCenter);
             cardLayout->addWidget(unlocksHeaderLabel);
 
-            QString unlocksText;
-            if (option.newlyUnlockedItemNames.empty())
+            if (option.newlyUnlockedRecipeIds.empty())
             {
-                unlocksText = tr("None");
+                QLabel* noneLabel = new QLabel(tr("None"), card);
+                noneLabel->setAlignment(Qt::AlignCenter);
+                cardLayout->addWidget(noneLabel);
             }
             else
             {
-                QStringList itemLines;
-                for (const std::string& itemName : option.newlyUnlockedItemNames)
+                for (const std::string& recipeId : option.newlyUnlockedRecipeIds)
                 {
-                    itemLines << QString::fromStdString(itemName);
+                    QLabel* recipeLabel = new QLabel(
+                        QString::fromStdString(toDisplayName(recipeId)), card);
+                    recipeLabel->setAlignment(Qt::AlignCenter);
+                    if (const RecipeDef* def = findRecipe(recipes, recipeId))
+                    {
+                        recipeLabel->setToolTip(buildRecipeTooltip(*def));
+                    }
+                    cardLayout->addWidget(recipeLabel);
                 }
-                unlocksText = itemLines.join("\n");
             }
-            QLabel* unlocksLabel = new QLabel(unlocksText, card);
-            unlocksLabel->setAlignment(Qt::AlignCenter);
-            cardLayout->addWidget(unlocksLabel);
         }
 
         QPushButton* selectButton = new QPushButton(tr("Select"), card);

src/ui/SchematicChoiceDialog.h

@@ -6,12 +6,15 @@
 
 #include "SchematicChoiceOption.h"
 
+struct RecipesConfig;
+
 class SchematicChoiceDialog : public QDialog
 {
     Q_OBJECT
 
 public:
     SchematicChoiceDialog(const std::vector<SchematicChoiceOption>& options,
+                          const RecipesConfig& recipes,
                           QWidget* parent = nullptr);
 
     int getChosenIndex() const;

src/ui/SelectedBuildingPanel.cpp

@@ -21,6 +21,7 @@
 #include "FactionComponent.h"
 #include "HealthComponent.h"
 #include "ModuleOwnerComponent.h"
+#include "SelectedBehaviorComponent.h"
 #include "ShipIdentityComponent.h"
 #include "ShipStatsCalculator.h"
 #include "ShipStatsPanel.h"
@@ -33,9 +34,11 @@
 #include "ItemType.h"
 #include "LayoutDialogRequestedEvent.h"
 #include "ModulesConfig.h"
+#include "PlayerCommandsAppliedEvent.h"
 #include "RecipeSelectionDialog.h"
 #include "RecipeSelectionRequestedEvent.h"
 #include "Rotation.h"
+#include "ScrapSystem.h"
 #include "ShipLayoutPreview.h"
 #include "Simulation.h"
 #include "WeaponComponent.h"
@@ -45,6 +48,11 @@ namespace
 
 QString buildingTypeName(BuildingType type)
 {
+    if (type == BuildingType::Hq)
+    {
+        return QObject::tr("Player HQ");
+    }
+
     const std::string id = buildingTypeId(type);
     QString result;
     bool nextUpper = true;
@@ -77,6 +85,25 @@ bool isProductionBuilding(BuildingType type)
         || type == BuildingType::Shipyard;
 }
 
+// Buildings that expose a player recipe/schematic selection control
+// (REQ-UI-SELECT-BUTTON): Miner ore type, Assembler recipe, Shipyard schematic.
+// The Smelter and Reprocessing Plant auto-process and offer no selection
+// (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING).
+bool hasRecipeSelection(BuildingType type)
+{
+    return type == BuildingType::Miner
+        || type == BuildingType::Assembler
+        || type == BuildingType::Shipyard;
+}
+
+// Auto-recipe buildings have no selected recipe; their production is driven by
+// whatever inputs they receive.
+bool isAutoRecipeBuilding(BuildingType type)
+{
+    return type == BuildingType::Smelter
+        || type == BuildingType::ReprocessingPlant;
+}
+
 bool isBeltLike(BuildingType type)
 {
     return type == BuildingType::Belt || type == BuildingType::Splitter
@@ -170,6 +197,10 @@ SelectedBuildingPanel::SelectedBuildingPanel(Simulation* sim,
     m_layout->addWidget(m_stationStatsLabel);
     m_stationStatsLabel->hide();
 
+    m_scrapLabel = new QLabel(this);
+    m_layout->addWidget(m_scrapLabel);
+    m_scrapLabel->hide();
+
     buildEmpty();
 
     registerForEvents();
@@ -186,6 +217,9 @@ void SelectedBuildingPanel::onSelectionChanged(const std::vector<BuildingId>& id
     if (!ids.empty())
     {
         clearEntityDisplay();
+        // A building selection supersedes any scrap selection (REQ-UI-SCRAP-CLICK-SELECT).
+        m_selectedScrap.clear();
+        m_scrapLabel->hide();
     }
     rebuild();
 }
@@ -218,6 +252,7 @@ void SelectedBuildingPanel::hideAllWidgets()
     m_filterBLabel->hide();
     m_filterBList->hide();
     m_buffersLabel->hide();
+    m_scrapLabel->hide();
 }
 
 void SelectedBuildingPanel::clearContent()
@@ -264,7 +299,7 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
     m_titleLabel->show();
     m_buffersLabel->show();
 
-    if (isProductionBuilding(type))
+    if (hasRecipeSelection(type))
     {
         const std::vector<RecipeSelectionOption> options =
             buildRecipeSelectionOptions(type, *m_sim, *m_config);
@@ -294,38 +329,12 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
         }
         m_recipeSelectButton->show();
 
-        if (type == BuildingType::Shipyard && !recipeId.empty())
-        {
-            const ShipDef* sDef = findShipDef(recipeId);
-            if (sDef && !sDef->layout.empty())
-            {
-                ShipLayoutConfig layout;
-                if (shipLayout.has_value())
-                {
-                    layout = *shipLayout;
-                }
-                m_layoutPreview->setShipAndLayout(
-                    sDef->layout, layout, &m_config->modules.modules);
-                m_layoutPreview->show();
-                m_configureLayoutBtn->show();
-            }
-            else
-            {
-                m_layoutPreview->hide();
-                m_configureLayoutBtn->hide();
-            }
-        }
-        else
-        {
-            m_layoutPreview->hide();
-            m_configureLayoutBtn->hide();
-        }
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
     }
     else
     {
         m_recipeSelectButton->hide();
-        m_layoutPreview->hide();
-        m_configureLayoutBtn->hide();
+        updateShipyardLayoutWidgets(type, recipeId, shipLayout);
     }
 
     // Belt "Clear" removes items from a live belt tile; a construction site has
@@ -363,32 +372,7 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
 
     if (m_singleIsSite)
     {
-        QString progress;
-        if (s->completesAt == 0)
-        {
-            progress = tr("Queued");
-        }
-        else
-        {
-            const BuildingDef* def = nullptr;
-            for (const BuildingDef& d : m_config->buildings.buildings)
-            {
-                if (d.type == s->type) { def = &d; break; }
-            }
-            if (def && def->constructionTimeSeconds > 0)
-            {
-                const Tick duration = secondsToTicks(def->constructionTimeSeconds);
-                const Tick elapsed  = m_sim->currentTick() - (s->completesAt - duration);
-                const int pct = static_cast<int>(
-                    std::max(Tick(0), std::min(duration, elapsed)) * 100 / duration);
-                progress = tr("%1% complete").arg(pct);
-            }
-            else
-            {
-                progress = tr("Building...");
-            }
-        }
-        m_buffersLabel->setText(progress);
+        refreshSiteProgress(s);
     }
     else
     {
@@ -396,6 +380,36 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
     }
 }
 
+void SelectedBuildingPanel::refreshSiteProgress(const ConstructionSite* s)
+{
+    QString progress;
+    if (s->completesAt == 0)
+    {
+        progress = tr("Queued");
+    }
+    else
+    {
+        const BuildingDef* def = nullptr;
+        for (const BuildingDef& d : m_config->buildings.buildings)
+        {
+            if (d.type == s->type) { def = &d; break; }
+        }
+        if (def && def->constructionTimeSeconds > 0)
+        {
+            const Tick duration = secondsToTicks(def->constructionTimeSeconds);
+            const Tick elapsed  = m_sim->currentTick() - (s->completesAt - duration);
+            const int pct = static_cast<int>(
+                std::max(Tick(0), std::min(duration, elapsed)) * 100 / duration);
+            progress = tr("%1% complete").arg(pct);
+        }
+        else
+        {
+            progress = tr("Building...");
+        }
+    }
+    m_buffersLabel->setText(progress);
+}
+
 void SelectedBuildingPanel::refreshBuffers(const Building* b)
 {
     const RecipeDef* recipe  = findRecipe(b);
@@ -403,6 +417,21 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
                                 ? findShipDef(b->recipeId)
                                 : nullptr;
 
+    // Auto-recipe buildings (Smelter, Reprocessing Plant) have no selected
+    // recipe; while a cycle runs, resolve the recipe actually in production so
+    // the cycle time and progress can be shown (REQ-UI-PRODUCTION-PROGRESS).
+    if (!recipe && isAutoRecipeBuilding(b->type) && b->production.has_value())
+    {
+        for (const RecipeDef& r : m_config->recipes.recipes)
+        {
+            if (r.id == b->production->recipeId && r.building == b->type)
+            {
+                recipe = &r;
+                break;
+            }
+        }
+    }
+
     QString bufText;
 
     if (!b->inputBuffer.counts.empty())
@@ -456,13 +485,24 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
         bufText += "\n";
     }
 
+    // Count output-side items: buffered plus still-emerging on the output belts.
+    // An emerging item still belongs to the output buffer (REQ-MAT-OUTPUT-EMERGE),
+    // so it must be included here or it would vanish from the panel while animating.
+    std::map<std::string, int> outCounts;
+    for (const Item& item : b->outputBuffer.items)
+    {
+        outCounts[item.type.id]++;
+    }
+    for (const std::vector<BeltItemSlot>& lane : b->emergingItems)
+    {
+        for (const BeltItemSlot& slot : lane)
+        {
+            outCounts[slot.item.type.id]++;
+        }
+    }
+
     if (recipe && !recipe->outputs.empty())
     {
-        std::map<std::string, int> outCounts;
-        for (const Item& item : b->outputBuffer.items)
-        {
-            outCounts[item.type.id]++;
-        }
         bufText += tr("Output: ");
         for (const RecipeOutput& out : recipe->outputs)
         {
@@ -474,13 +514,8 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
                 + "/" + QString::number(out.amount) + "  ";
         }
     }
-    else if (!b->outputBuffer.items.empty())
+    else if (!outCounts.empty())
     {
-        std::map<std::string, int> outCounts;
-        for (const Item& item : b->outputBuffer.items)
-        {
-            outCounts[item.type.id]++;
-        }
         bufText += tr("Output: ");
         for (const std::pair<const std::string, int>& entry : outCounts)
         {
@@ -489,57 +524,102 @@ void SelectedBuildingPanel::refreshBuffers(const Building* b)
         }
     }
 
-    if (isProductionBuilding(b->type) && (recipe || shipDef))
+    if (isProductionBuilding(b->type)
+        && (recipe || shipDef || isAutoRecipeBuilding(b->type)))
     {
-        double durationSeconds = recipe
-            ? recipe->durationSeconds
-            : shipDef->schematic.productionTimeSeconds;
-
-        if (shipDef && b->shipLayout.has_value())
+        if (recipe || shipDef)
         {
-            for (const PlacedModule& pm : b->shipLayout->placedModules)
+            double durationSeconds = recipe
+                ? recipe->durationSeconds
+                : shipDef->schematic.productionTimeSeconds;
+
+            if (shipDef && b->shipLayout.has_value())
             {
-                for (const ModuleDef& modDef : m_config->modules.modules)
+                for (const PlacedModule& pm : b->shipLayout->placedModules)
                 {
-                    if (modDef.id == pm.moduleId)
+                    for (const ModuleDef& modDef : m_config->modules.modules)
                     {
-                        durationSeconds += modDef.productionTimeSeconds;
-                        break;
+                        if (modDef.id == pm.moduleId)
+                        {
+                            durationSeconds += modDef.productionTimeSeconds;
+                            break;
+                        }
                     }
                 }
             }
-        }
 
-        bufText += tr("Cycle: %1 s\n").arg(durationSeconds, 0, 'f', 1);
+            bufText += tr("Cycle: %1 s\n").arg(durationSeconds, 0, 'f', 1);
 
-        if (b->production.has_value())
-        {
-            const Tick cycleTicks  = secondsToTicks(durationSeconds);
-            const Tick completesAt = b->production->completesAt;
-            const Tick currentTick = m_sim->currentTick();
-            const Tick elapsed     = currentTick - (completesAt - cycleTicks);
-            const int  pct         = static_cast<int>(
-                std::max(Tick(0), std::min(cycleTicks, elapsed)) * 100 / cycleTicks);
-            bufText += tr("Progress: %1%\n").arg(pct);
+            if (b->production.has_value())
+            {
+                const Tick cycleTicks  = secondsToTicks(durationSeconds);
+                const Tick completesAt = b->production->completesAt;
+                const Tick currentTick = m_sim->currentTick();
+                const Tick elapsed     = currentTick - (completesAt - cycleTicks);
+                const int  pct         = static_cast<int>(
+                    std::max(Tick(0), std::min(cycleTicks, elapsed)) * 100 / cycleTicks);
+                bufText += tr("Progress: %1%\n").arg(pct);
+            }
+            else
+            {
+                bufText += tr("Progress: idle\n");
+            }
         }
         else
         {
+            // Auto-recipe building with no active cycle: no single recipe to
+            // show a cycle time for.
             bufText += tr("Progress: idle\n");
         }
     }
 
     m_buffersLabel->setText(bufText);
 
-    if (b->type == BuildingType::Shipyard && shipDef && !shipDef->layout.empty())
+    // The recipe/schematic is applied via a queued command that only drains on a
+    // later frame, so the per-tick refresh must own the shipyard preview and the
+    // Configure Layout button's visibility; otherwise they stay hidden until the
+    // building is re-selected (which re-runs buildSingle).
+    updateShipyardLayoutWidgets(b->type, b->recipeId, b->shipLayout);
+}
+
+void SelectedBuildingPanel::updateShipyardLayoutWidgets(
+    BuildingType type,
+    const std::string& recipeId,
+    const std::optional<ShipLayoutConfig>& shipLayout)
+{
+    // The preview and Configure button are shipyard-only controls; hide them
+    // entirely for other building types.
+    if (type != BuildingType::Shipyard)
+    {
+        m_layoutPreview->hide();
+        m_configureLayoutBtn->hide();
+        return;
+    }
+
+    const ShipDef* shipDef = findShipDef(recipeId);
+    const bool hasSchematic = shipDef && !shipDef->layout.empty();
+
+    // Always show the preview and Configure button for a shipyard; they are only
+    // enabled once a schematic is selected (REQ-MOD-UI-PREVIEW).
+    if (hasSchematic)
     {
         ShipLayoutConfig layout;
-        if (b->shipLayout.has_value())
+        if (shipLayout.has_value())
         {
-            layout = *b->shipLayout;
+            layout = *shipLayout;
         }
         m_layoutPreview->setShipAndLayout(
             shipDef->layout, layout, &m_config->modules.modules);
     }
+    else
+    {
+        m_layoutPreview->showPlaceholder();
+    }
+
+    m_layoutPreview->setEnabled(hasSchematic);
+    m_configureLayoutBtn->setEnabled(hasSchematic);
+    m_layoutPreview->show();
+    m_configureLayoutBtn->show();
 }
 
 const RecipeDef* SelectedBuildingPanel::findRecipe(const Building* b) const
@@ -564,6 +644,28 @@ const ShipDef* SelectedBuildingPanel::findShipDef(const std::string& id) const
 
 void SelectedBuildingPanel::handleEvent(std::shared_ptr<const TickAdvancedEvent> /*event*/)
 {
+    refreshSelectionDisplay(RefreshReason::PeriodicTick);
+}
+
+void SelectedBuildingPanel::handleEvent(
+    std::shared_ptr<const PlayerCommandsAppliedEvent> /*event*/)
+{
+    // Player commands (e.g. choosing a shipyard schematic) are applied by a
+    // queued drain, not synchronously. When the game is paused no tick advances,
+    // so TickAdvancedEvent never fires; refresh here too, otherwise the panel
+    // would not reflect the change until the next tick or a re-selection.
+    refreshSelectionDisplay(RefreshReason::CommandApplied);
+}
+
+void SelectedBuildingPanel::refreshSelectionDisplay(RefreshReason reason)
+{
+    if (!m_selectedScrap.empty())
+    {
+        // The total shrinks live as piles are collected or despawn (REQ-UI-SCRAP-PANEL).
+        refreshScrapTotal();
+        return;
+    }
+
     if (m_selectedEntity.has_value())
     {
         refreshEntityStats();
@@ -587,7 +689,18 @@ void SelectedBuildingPanel::handleEvent(std::shared_ptr<const TickAdvancedEvent>
     const ConstructionSite* s = m_sim->buildings().findSite(m_singleBuildingId);
     if (s)
     {
-        rebuild();
+        // A periodic tick only advances construction progress, so update just the
+        // progress label. Rebuilding every tick would hide/re-show all widgets and
+        // cancel any in-progress click on the recipe button. An applied command
+        // may have changed the site's recipe/layout, so rebuild in that case.
+        if (reason == RefreshReason::CommandApplied)
+        {
+            rebuild();
+        }
+        else
+        {
+            refreshSiteProgress(s);
+        }
         return;
     }
     buildEmpty();
@@ -621,6 +734,7 @@ void SelectedBuildingPanel::buildMulti(const std::vector<BuildingId>& ids)
     }
 
     bool hasBelt = false;
+    int totalCost = 0;
     QString text;
     for (const std::pair<const BuildingType, int>& entry : counts)
     {
@@ -630,7 +744,15 @@ void SelectedBuildingPanel::buildMulti(const std::vector<BuildingId>& ids)
         {
             hasBelt = true;
         }
+        // Total placement cost counts only player-placeable buildings; the HQ
+        // and defence stations are excluded (REQ-UI-MULTI-SELECTION).
+        const BuildingDef* def = m_config->buildings.findBuildingDef(entry.first);
+        if (def && def->playerPlaceable)
+        {
+            totalCost += def->cost * entry.second;
+        }
     }
+    text += tr("Total: %1 Building Blocks").arg(totalCost);
     m_titleLabel->setText(text.trimmed());
     m_titleLabel->show();
 
@@ -647,9 +769,11 @@ void SelectedBuildingPanel::onSelectRecipeClicked()
         return;
     }
     // The emit is synchronous: MainWindow pauses the game, runs the modal
-    // selection dialog, applies the chosen recipe/schematic, and restores the
-    // speed before this returns. rebuild() then refreshes the button caption,
-    // tooltip, preview, and buffers for the new selection.
+    // selection dialog, and restores the speed before this returns. The chosen
+    // recipe/schematic is only *enqueued* as a command, though, and drains on a
+    // later frame -- so this rebuild() still sees the old recipe. The per-tick
+    // refreshBuffers() path picks up the new schematic (and shows the layout
+    // preview + Configure Layout button) once the command has been applied.
     EventManager::getInstance()->sendEventImmediately(
         std::make_shared<RecipeSelectionRequestedEvent>(m_singleBuildingId));
     rebuild();
@@ -789,6 +913,9 @@ void SelectedBuildingPanel::handleEvent(std::shared_ptr<const EntitySelectedEven
     {
         m_selectedEntity = event->entity;
         m_selectedBuildingIds.clear();
+        // An entity selection supersedes any scrap selection (REQ-UI-SCRAP-CLICK-SELECT).
+        m_selectedScrap.clear();
+        m_scrapLabel->hide();
         clearContent();
 
         EntityAdmin& admin = m_sim->admin();
@@ -827,6 +954,8 @@ void SelectedBuildingPanel::buildEntityShip(entt::entity entity)
 
     const ShipStats stats = buildShipStatsFromEntity(admin, entity);
     m_entityStatsPanel->refreshFromLive(stats, health.hp);
+    m_entityStatsPanel->setBehavior(
+        admin.get<SelectedBehaviorComponent>(entity).winner);
     m_entityStatsPanel->setDebugDrawEnabled(m_debugDraw);
 
     for (const ShipDef& def : m_config->ships.ships)
@@ -850,7 +979,11 @@ void SelectedBuildingPanel::buildEntityStation(entt::entity entity)
     EntityAdmin& admin = m_sim->admin();
     const HealthComponent& health = admin.get<HealthComponent>(entity);
 
-    m_entityTitleLabel->setText(tr("Defence Station"));
+    const bool isEnemy = admin.hasAll<FactionComponent>(entity)
+        && admin.get<FactionComponent>(entity).isEnemy;
+    m_entityTitleLabel->setText(isEnemy
+        ? tr("Enemy Defence Station")
+        : tr("Player Defence Station"));
     m_entityTitleLabel->show();
 
     float totalDps = 0.0f;
@@ -906,6 +1039,8 @@ void SelectedBuildingPanel::refreshEntityStats()
     {
         const ShipStats stats = buildShipStatsFromEntity(admin, entity);
         m_entityStatsPanel->refreshFromLive(stats, health.hp);
+        m_entityStatsPanel->setBehavior(
+            admin.get<SelectedBehaviorComponent>(entity).winner);
     }
     else if (admin.hasAll<StationBodyComponent>(entity))
     {
@@ -926,6 +1061,54 @@ void SelectedBuildingPanel::handleEvent(std::shared_ptr<const SelectionChangedEv
     onSelectionChanged(event->ids);
 }
 
+void SelectedBuildingPanel::handleEvent(
+    std::shared_ptr<const ScrapSelectionChangedEvent> event)
+{
+    m_selectedScrap = event->scrap;
+    if (!m_selectedScrap.empty())
+    {
+        // Scrap is its own selection category, mutually exclusive with buildings and
+        // entities (REQ-UI-SCRAP-CLICK-SELECT).
+        m_selectedBuildingIds.clear();
+        clearContent();
+        clearEntityDisplay();
+        buildScrap();
+    }
+    else
+    {
+        m_scrapLabel->hide();
+        if (m_selectedBuildingIds.empty() && !m_selectedEntity.has_value())
+        {
+            buildEmpty();
+        }
+    }
+}
+
+void SelectedBuildingPanel::buildScrap()
+{
+    clearContent();
+    m_entityTitleLabel->hide();
+    m_entityStatsPanel->hide();
+    m_stationStatsLabel->hide();
+    refreshScrapTotal();
+    m_scrapLabel->show();
+}
+
+void SelectedBuildingPanel::refreshScrapTotal()
+{
+    // Sum the remaining amounts of the still-living selected piles (REQ-UI-SCRAP-PANEL).
+    int total = 0;
+    for (const ScrapInfo& info : m_sim->scraps().allScrapInfo())
+    {
+        if (std::find(m_selectedScrap.begin(), m_selectedScrap.end(), info.entity)
+            != m_selectedScrap.end())
+        {
+            total += info.amount;
+        }
+    }
+    m_scrapLabel->setText(tr("Scrap: %1").arg(total));
+}
+
 void SelectedBuildingPanel::handleEvent(std::shared_ptr<const DebugDrawToggledEvent> event)
 {
     m_debugDraw = event->active;

src/ui/SelectedBuildingPanel.h

@@ -16,7 +16,9 @@
 #include "EntitySelectedEvent.h"
 #include "EventHandler.h"
 #include "GameConfig.h"
+#include "PlayerCommandsAppliedEvent.h"
 #include "RecipesConfig.h"
+#include "ScrapSelectionChangedEvent.h"
 #include "SelectionChangedEvent.h"
 #include "ShipLayout.h"
 #include "ShipsConfig.h"
@@ -33,8 +35,10 @@ class QVBoxLayout;
 
 class SelectedBuildingPanel : public QWidget,
                                public CombinedEventHandler<TickAdvancedEvent,
+                                                           PlayerCommandsAppliedEvent,
                                                            EntitySelectedEvent,
                                                            SelectionChangedEvent,
+                                                           ScrapSelectionChangedEvent,
                                                            DebugDrawToggledEvent>
 {
     Q_OBJECT
@@ -46,8 +50,10 @@ public:
 
 private:
     void handleEvent(std::shared_ptr<const TickAdvancedEvent> event) override;
+    void handleEvent(std::shared_ptr<const PlayerCommandsAppliedEvent> event) override;
     void handleEvent(std::shared_ptr<const EntitySelectedEvent> event) override;
     void handleEvent(std::shared_ptr<const SelectionChangedEvent> event) override;
+    void handleEvent(std::shared_ptr<const ScrapSelectionChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const DebugDrawToggledEvent> event) override;
 
 private slots:
@@ -56,14 +62,31 @@ private slots:
     void onSplitterFilterChanged();
 
 private:
+    // Why the selection display is being refreshed. A periodic tick only needs a
+    // lightweight content update (e.g. a construction site's progress label),
+    // whereas an applied player command may have changed the configuration and
+    // needs a full structural rebuild.
+    enum class RefreshReason
+    {
+        PeriodicTick,
+        CommandApplied
+    };
+
     void onSelectionChanged(const std::vector<BuildingId>& ids);
+    void refreshSelectionDisplay(RefreshReason reason);
     void rebuild();
     void hideAllWidgets();
     void clearContent();
     void buildEmpty();
     void buildSingle(BuildingId id);
     void buildMulti(const std::vector<BuildingId>& ids);
+    void buildScrap();
+    void refreshScrapTotal();
     void refreshBuffers(const Building* b);
+    void refreshSiteProgress(const ConstructionSite* s);
+    void updateShipyardLayoutWidgets(BuildingType type,
+                                     const std::string& recipeId,
+                                     const std::optional<ShipLayoutConfig>& shipLayout);
     void buildSplitterFilters(const std::optional<BeltSystem::SplitterInfo>& info);
     const RecipeDef* findRecipe(const Building* b) const;
     const ShipDef*   findShipDef(const std::string& id) const;
@@ -97,6 +120,9 @@ private:
     QLabel*         m_entityTitleLabel;
     QLabel*         m_stationStatsLabel;
 
+    std::vector<entt::entity> m_selectedScrap;
+    QLabel*                   m_scrapLabel;
+
     void buildEntityShip(entt::entity entity);
     void buildEntityStation(entt::entity entity);
     void refreshEntityStats();

src/ui/ShipLayoutDialog.cpp

@@ -461,6 +461,10 @@ ShipLayoutDialog::ShipLayoutDialog(const GameConfig* config,
         QPushButton* btn = new QPushButton(label, this);
         btn->setCheckable(true);
         btn->setFixedHeight(48);
+        if (def.tooltip)
+        {
+            btn->setToolTip(QString::fromStdString(*def.tooltip));
+        }
         buttonGrid->addWidget(btn, row, col);
         m_moduleButtons.push_back(btn);
 

src/ui/ShipLayoutPreview.cpp

@@ -8,6 +8,10 @@ namespace
 
 const int kCellSize = 8;
 
+// Size of the empty placeholder box shown when no schematic is selected.
+const int kPlaceholderWidth  = 64;
+const int kPlaceholderHeight = 40;
+
 const ModuleDef* findModuleDef(const std::vector<ModuleDef>& modules,
                                const std::string& id)
 {
@@ -90,14 +94,28 @@ void ShipLayoutPreview::clear()
     m_modules = nullptr;
     m_rows = 0;
     m_cols = 0;
+    m_placeholder = false;
     setFixedSize(0, 0);
     update();
 }
 
+void ShipLayoutPreview::showPlaceholder()
+{
+    m_grid.clear();
+    m_placedModules.clear();
+    m_modules = nullptr;
+    m_rows = 0;
+    m_cols = 0;
+    m_placeholder = true;
+    setFixedSize(kPlaceholderWidth, kPlaceholderHeight);
+    update();
+}
+
 void ShipLayoutPreview::setShipAndLayout(const std::vector<std::string>& shipLayout,
                                          const ShipLayoutConfig& layout,
                                          const std::vector<ModuleDef>* modules)
 {
+    m_placeholder = false;
     m_modules = modules;
     m_placedModules = layout.placedModules;
     m_rows = static_cast<int>(shipLayout.size());
@@ -156,6 +174,18 @@ void ShipLayoutPreview::setShipAndLayout(const std::vector<std::string>& shipLay
 
 void ShipLayoutPreview::paintEvent(QPaintEvent* /*event*/)
 {
+    if (m_placeholder)
+    {
+        QPainter painter(this);
+        painter.setRenderHint(QPainter::Antialiasing, false);
+        const QRect box = rect().adjusted(0, 0, -1, -1);
+        painter.fillRect(box, QColor(40, 40, 40));
+        painter.setPen(QColor(128, 128, 128));
+        painter.drawRect(box);
+        painter.drawText(box, Qt::AlignCenter, tr("No schematic"));
+        return;
+    }
+
     if (m_rows == 0 || m_cols == 0)
     {
         return;

src/ui/ShipLayoutPreview.h

@@ -20,6 +20,10 @@ public:
                           const std::vector<ModuleDef>* modules);
     void clear();
 
+    // Shows an empty placeholder box (no ship layout) so the preview stays
+    // visible while no schematic is selected (REQ-MOD-UI-PREVIEW).
+    void showPlaceholder();
+
 protected:
     void paintEvent(QPaintEvent* event) override;
 
@@ -35,4 +39,5 @@ private:
     const std::vector<ModuleDef>* m_modules;
     int m_rows;
     int m_cols;
+    bool m_placeholder = false;
 };

src/ui/ShipStatsPanel.cpp

@@ -107,6 +107,12 @@ ShipStatsPanel::ShipStatsPanel(const GameConfig* config, QWidget* parent)
     m_repairSection->setVisible(false);
     layout->addWidget(m_repairSection);
 
+	// Current behavior — live entities only; hidden in the static design
+	// preview (REQ-UI-SHIP-BEHAVIOR).
+	m_behaviorLabel = makeSectionHeader(QString(), this);
+	m_behaviorLabel->setVisible(false);
+	layout->addWidget(m_behaviorLabel);
+
     // Threat cost — debug-only, initially hidden.
     m_threatCostLabel = makeStatLabel(this);
     m_threatCostLabel->setVisible(false);
@@ -125,6 +131,9 @@ void ShipStatsPanel::refresh(const std::string& shipId,
     const double threat = calculateShipThreatCost(m_config->threatCosts, *m_config,
                                                   shipId, modules);
     setThreatCost(threat);
+
+    // The static design preview has no live behavior to show.
+    m_behaviorLabel->setVisible(false);
 }
 
 void ShipStatsPanel::refreshFromLive(const ShipStats& stats, float currentHp)
@@ -204,6 +213,32 @@ void ShipStatsPanel::applyStats(const ShipStats& stats, const QString& hpText)
     }
 }
 
+void ShipStatsPanel::setBehavior(BehaviorKind kind)
+{
+    QString label;
+    switch (kind)
+    {
+        case BehaviorKind::Retreat:      label = tr("Retreating"); break;
+        case BehaviorKind::Attack:       label = tr("Engaging");   break;
+        case BehaviorKind::SalvageScrap:
+        case BehaviorKind::DeliverScrap: label = tr("Salvaging");  break;
+        case BehaviorKind::Repair:       label = tr("Repairing");  break;
+        case BehaviorKind::Rally:        label = tr("Rallying");   break;
+        case BehaviorKind::Standby:      label = tr("Standby");    break;
+        case BehaviorKind::Advance:      label = tr("Advancing");  break;
+        case BehaviorKind::None:         break;
+    }
+
+    if (label.isEmpty())
+    {
+        m_behaviorLabel->setVisible(false);
+        return;
+    }
+
+    m_behaviorLabel->setText(tr("Behavior: %1").arg(label));
+    m_behaviorLabel->setVisible(true);
+}
+
 void ShipStatsPanel::setThreatCost(double cost)
 {
     m_threatCostLabel->setText(tr("Threat Cost: %1").arg(cost, 0, 'f', 1));

src/ui/ShipStatsPanel.h

@@ -6,6 +6,7 @@
 
 #include <QWidget>
 
+#include "BehaviorKind.h"
 #include "ShipLayout.h"
 #include "ShipStatsCalculator.h"
 
@@ -24,6 +25,9 @@ public:
 
     void refreshFromLive(const ShipStats& stats, float currentHp);
 
+    // Displays the ship's current top-priority behavior (REQ-UI-SHIP-BEHAVIOR).
+    void setBehavior(BehaviorKind kind);
+
     void setThreatCost(double cost);
     void setDebugDrawEnabled(bool enabled);
 
@@ -33,6 +37,7 @@ private:
     const GameConfig* m_config;
     bool m_debugDraw = false;
 
+    QLabel* m_behaviorLabel;
     QLabel* m_hpLabel;
     QLabel* m_speedLabel;
     QLabel* m_sensorRangeLabel;

src/ui/VisualsConfig.h

@@ -48,6 +48,9 @@ struct OverlayVisuals
     QColor selectionRect;
     QColor tileHighlight;
     QColor selectedOutline;
+    QColor copyConfig;
+    QColor lockedAsteroid;
+    QColor modalDim;
 };
 
 struct ToastVisuals

src/ui/VisualsLoader.cpp

@@ -224,6 +224,9 @@ VisualsConfig VisualsLoader::load(const std::string& path)
         cfg.overlays.selectionRect   = parseColor(requireString(ov, "selection_rect",   "overlays"), "overlays.selection_rect");
         cfg.overlays.tileHighlight   = parseColor(requireString(ov, "tile_highlight",   "overlays"), "overlays.tile_highlight");
         cfg.overlays.selectedOutline = parseColor(requireString(ov, "selected_outline", "overlays"), "overlays.selected_outline");
+        cfg.overlays.copyConfig      = parseColor(requireString(ov, "copy_config",      "overlays"), "overlays.copy_config");
+        cfg.overlays.lockedAsteroid  = parseColor(requireString(ov, "locked_asteroid",  "overlays"), "overlays.locked_asteroid");
+        cfg.overlays.modalDim        = parseColor(requireString(ov, "modal_dim",        "overlays"), "overlays.modal_dim");
     }
 
     // Toast