draw glyph for output port at the target tile during build mode

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
@@ -78,6 +87,7 @@ 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

bin/app/data/config/modules.toml

@@ -32,6 +32,7 @@
 
 [[module]]
 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 = "railgun_s_module", amount = 1}]
@@ -47,6 +48,7 @@ attack_rate_hz = 2.0
 
 [[module]]
 id = "railgun_m"
+tooltip = "Medium railgun. Higher damage at longer range; needs a 2x2 slot."
 unlock_at_station_level = 2
 surface_mask = [
     "OO",
@@ -64,6 +66,7 @@ attack_rate_hz = 1.5
 
 [[module]]
 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 = [
@@ -86,6 +89,7 @@ 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}]
@@ -101,6 +105,7 @@ collection_rate_hz = 0.5
 
 [[module]]
 id = "repair_tool"
+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}]
@@ -119,6 +124,7 @@ repair_range_m = 80
 
 [[module]]
 id = "afterburner"
+tooltip = "Greatly boosts top speed and forward acceleration."
 unlock_at_station_level = 2
 surface_mask = ["OOO"]
 materials = [{item = "afterburner_module", amount = 1}]
@@ -133,6 +139,7 @@ added_main_acceleration_mpss = 60
 
 [[module]]
 id = "maneuvering_thrusters"
+tooltip = "Improves top speed and lateral/braking acceleration."
 unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "maneuvering_thrusters_module", amount = 1}]
@@ -150,6 +157,7 @@ added_maneuvering_acceleration_mpss = 10
 
 [[module]]
 id = "armor_plates"
+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}]
@@ -163,6 +171,7 @@ added_hp = 1200
 
 [[module]]
 id = "sensor_booster"
+tooltip = "Extends the ship's sensor range."
 unlock_at_station_level = 1
 surface_mask = ["OO"]
 materials = [{item = "sensor_booster_module", amount = 1}]
@@ -179,6 +188,7 @@ added_sensor_range_m = 50
 
 [[module]]
 id = "weapon_upgrade"
+tooltip = "Increases the damage of all weapons on the ship."
 unlock_at_station_level = 4
 surface_mask = [
     "OO",
@@ -195,6 +205,7 @@ multiplied_damage = 1.2
 
 [[module]]
 id = "weapon_primer"
+tooltip = "Increases the fire rate of all weapons on the ship."
 unlock_at_station_level = 4
 surface_mask = [
     "OO",
@@ -211,6 +222,7 @@ multiplied_attack_rate_hz = 1.2
 
 [[module]]
 id = "weapon_stabilizer"
+tooltip = "Extends weapon range at the cost of some fire rate."
 unlock_at_station_level = 3
 surface_mask = [
     "OO",
@@ -234,6 +246,7 @@ multiplied_attack_rate_hz = 0.8
 
 [[module]]
 id = "drone_bay"
+tooltip = "Drone launch bay (capability not yet implemented)."
 unlock_at_station_level = 5
 surface_mask = [
     "OO",
@@ -246,6 +259,7 @@ glyph = "Db"
 
 [[module]]
 id = "drone_hangar"
+tooltip = "Large drone hangar (capability not yet implemented)."
 unlock_at_station_level = 9
 surface_mask = [
     "OOOOOO",

bin/app/data/config/visuals.toml

@@ -349,6 +349,8 @@ selection_rect = "#00ff00"     # box-drag selection rectangle (REQ-UI-MULTI-SELE
 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

@@ -10,6 +10,8 @@ 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 assemblers and deliver them to the HQ on a belt to grow your stock."
+artifact_tooltip = "Artifacts are the key to victory. Earn one by choosing the artifact reward when you destroy a set of enemy defence stations. Collect enough of them to win the game."
 
 [regions]
 asteroid_width_tiles = 60
@@ -20,8 +22,8 @@ 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 = 8.0
-pan_speed_fast_tiles_per_second = 24.0
+pan_speed_slow_tiles_per_second = 16.0
+pan_speed_fast_tiles_per_second = 32.0
 pan_ramp_band_width_tiles = 16
 
 [expansion]

bin/test/data/config/buildings.toml

@@ -84,6 +84,7 @@ 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/world.toml

@@ -10,6 +10,8 @@ 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."
+artifact_tooltip = "Choose the artifact reward when destroying enemy stations; collect enough to win."
 
 [regions]
 asteroid_width_tiles = 40

docs/architecture.md

@@ -97,6 +97,12 @@ All UI interactions — building selection, builder/blueprint mode transitions,
 
 Bidirectional interactions use separate request/notification event types to avoid infinite recursion (e.g., `ExitBuilderModeRequestedEvent` from `BuildButtonGrid` → `GameWorldView`, vs. `BuilderModeExitedEvent` from `GameWorldView` → `BuildButtonGrid`).
 
+### Reading Simulation State
+
+The simulation is the single source of truth for every game value (building block stock, expansion cost, threat level, tick, etc.). A UI widget that needs such a value holds the `Simulation*` it was constructed with and **pulls the value on demand** via the corresponding getter (e.g., `m_sim->getBuildingBlocksStock()`), rather than caching its own copy.
+
+State-change events (e.g., `BuildingBlocksChangedEvent`) are treated as *refresh signals*, not as carriers of truth: a widget subscribes to the event to learn *when* the value changed and then re-reads it from the simulation to learn *what* it now is. The value carried in the event payload is not authoritative and should not be stored. This keeps a single copy of each value and avoids stale-cache bugs (a widget acting on a value that has since moved on because nothing refreshed its local copy).
+
 ## Tick Order
 
 Within a single simulation tick, subsystems run in this fixed order. The order is load-bearing for determinism and for avoiding one-tick-delay artifacts (e.g., items landing on a belt but not advancing in the same tick).

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, artifact win count, and view pan speeds (slow and fast horizontal pan speed and pan ramp band width).
-- **buildings.toml** — building block cost and construction time per building type.
+- **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), an optional building blocks tooltip string (shown as the header bar's building blocks stock hover tooltip, REQ-UI-BLOCKS-TOOLTIP; omitted when unset), and an optional artifact tooltip string (shown as the header bar's artifact count hover tooltip, REQ-UI-ARTIFACTS-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, 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).
+- **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`.
@@ -127,14 +127,14 @@ Modules in `modules.toml` define a `surface_mask` — a list of strings that des
 - 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. 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).
-- 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-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.
@@ -146,9 +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.
@@ -259,7 +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:
@@ -269,6 +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:
@@ -401,11 +423,16 @@ The screen is divided into two columns: a main column (75% width) containing the
 ```
 
 - 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-ARTIFACTS-TOOLTIP: The header bar's artifact count display (REQ-UI-HEADER) shows a hover tooltip with the descriptive text defined in `world.toml [world].artifact_tooltip` — intended to tell the player what artifacts are, how they are obtained (REQ-DEF-SCHEMATIC-DROP), and that collecting `world.toml [world].artifact_win_count` of them wins the game (REQ-WIN-ARTIFACT-COUNT). If the field is unset, the artifact count display shows no tooltip. This tooltip is distinct from the building blocks tooltip (REQ-UI-BLOCKS-TOOLTIP) and 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-SPEED: The game speed controls in the header bar are buttons for 0×, 0.5×, 1×, 2×, and 10× 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-PAUSE-BORDER: While the game is paused (speed 0×, whether set via the speed controls (REQ-UI-SPEED), the Space toggle (REQ-UI-HOTKEYS), or an auto-pausing modal), a vignette border is drawn around the edges of the game world view to make the paused state hard to miss. The border is black and fades in the alpha channel from fully transparent at its inner (center-facing) edge to 50% opacity at the viewport edge, over a thickness of 100 pixels (capped at half the smaller viewport dimension on very small views).
+- REQ-UI-DEMOLISH-BORDER: While demolish mode is active (REQ-UI-DEMOLISH-BUTTON, REQ-UI-HOTKEYS), a vignette border is drawn around the edges of the game world view to signal the mode, matching the geometry of the paused-state vignette (REQ-UI-PAUSE-BORDER): a 100-pixel thickness (capped at half the smaller viewport dimension on very small views) with the four sides meeting along mitred corner diagonals. It fades in the alpha channel from fully transparent at its inner (center-facing) edge to the demolish tint color at the viewport edge. The color — including its alpha, which sets the peak opacity at the viewport edge — is read from `visuals.toml [overlays].demolish_tint`, the same demolish-mode color used for the hover tint. The border is presentation-only and has no effect on the simulation. If the game is both paused and in demolish mode, both vignettes are drawn and compose over each other.
 - 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
 
@@ -418,11 +445,12 @@ The screen is divided into two columns: a main column (75% width) containing the
   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-PORT-TARGET-GLYPH: While in builder mode (REQ-BLD-BUILDER-MODE), the builder-mode ghost additionally shows, for each of the building's output ports, a directional glyph drawn centered in the port's **target cell** — the cell immediately outside the footprint that the port pushes into, i.e. the cell the surface-mask output-port indicator occupies (see Surface Mask Format). As in REQ-UI-PORT-GLYPH the glyph is a `>` rotated to face the port's exit direction (`>` East, `^` North, `<` West, `v` South), previewing where the port's output will go before placement. This is in addition to the on-tile port glyph of REQ-UI-PORT-GLYPH, and — unlike that indicator — is shown only for the builder-mode ghost, not for operational buildings, construction sites, or the blueprint-placement ghost (REQ-UI-BLUEPRINT-PLACE). A building with multiple output ports (e.g. a splitter) shows one target-cell glyph per port. The target-cell glyph is drawn larger than the on-tile port glyph so it stands out as the flow-direction preview. Exceptions: the Tunnel Entry shows no target-cell glyph, because it receives items (which may arrive from any of its non-mouth edges, REQ-BLD-TUNNEL-ENTRY) rather than emitting into a single adjacent cell; the Shipyard shows none either, because its output port is a ship-spawn point (REQ-SHP-SPAWN-PLAYER) rather than a belt-item output (REQ-MAT-OUTPUT-EMERGE).
 - 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.
 - REQ-UI-NO-ZOOM: The view has a fixed zoom level; the player cannot zoom in or out.
 - REQ-UI-HOTKEYS: Global keyboard shortcuts:
   - **Space** — toggles pause. Pressing Space pauses (sets speed to 0×) and stores the previously selected non-zero speed; pressing Space again restores that speed.
-  - **W** — increases game speed by one step in the sequence 0×, 0.5×, 1×, 2×, 4× (no wrap-around past 4×).
+  - **W** — increases game speed by one step in the sequence 0×, 0.5×, 1×, 2×, 10× (no wrap-around past 10×).
   - **S** — decreases game speed by one step in the same sequence (no wrap-around past 0×).
   - **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.)
@@ -454,25 +482,37 @@ 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.
 
@@ -480,11 +520,11 @@ The screen is divided into two columns: a main column (75% width) containing the
 
 - 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-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. 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-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.
 
@@ -524,7 +564,7 @@ A separate executable target (`balancing`) that links against `lib` but contains
 
 - REQ-BAL-SIM-ENV: Each arena simulates a pure-space environment using the same tick-based simulation as the main game. There is no asteroid, no buildings, no belts, no wave system, and no threat accumulation. Only ships, HQs, defence stations, and combat are active.
 - REQ-BAL-SIM-AI: Ships use the same AI and stats as in the main game. Ships with no target in sensor range advance toward the enemy team's HQ. Ships that detect an enemy in sensor range engage it as in the normal game (REQ-SHP-COMBAT, REQ-SHP-ENEMY-AI).
-- REQ-BAL-SIM-SPEED: Each arena that is not being inspected runs its simulation at maximum tick rate (as many ticks per second as the hardware allows), with no rendering. An inspected arena runs at a player-controllable game speed (same speed steps as the main game: 0×, 0.5×, 1×, 2×, 4×) with full rendering in the inspect window, defaulting to 1× on open.
+- REQ-BAL-SIM-SPEED: Each arena that is not being inspected runs its simulation at maximum tick rate (as many ticks per second as the hardware allows), with no rendering. An inspected arena runs at a player-controllable game speed (same speed steps as the main game: 0×, 0.5×, 1×, 2×, 10×) with full rendering in the inspect window, defaulting to 1× on open.
 - REQ-BAL-SIM-PARALLEL: All arenas are simulated in parallel, each on its own thread.
 - REQ-BAL-SIM-END: An arena fight ends when either team's HQ is destroyed or all ships and defence stations of one team have been destroyed. If a team has no defence stations, destroying all its ships is sufficient. When the fight ends, the simulation for that arena stops.
 
@@ -541,6 +581,6 @@ A separate executable target (`balancing`) that links against `lib` but contains
 - 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, including the arena's battle duration once the fight has ended (REQ-BAL-UI-WIDGET).
+- 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×, 10×, 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/balancing/ArenaSimulation.cpp

@@ -95,7 +95,7 @@ ArenaSimulation::ArenaSimulation(const GameConfig& gameConfig,
     updateStatus();
 }
 
-std::string ArenaStatus::TeamStatus::ehpPercentText() const
+std::string ArenaStatus::TeamStatus::getEhpPercentText() const
 {
     if (maxEhp <= 0.0)
     {
@@ -312,7 +312,7 @@ void ArenaSimulation::requestStop()
     m_stopRequested.store(true, std::memory_order_relaxed);
 }
 
-ArenaStatus ArenaSimulation::status() const
+ArenaStatus ArenaSimulation::getStatus() const
 {
     std::lock_guard<std::mutex> lock(m_statusMutex);
     return m_status;
@@ -473,42 +473,42 @@ bool ArenaSimulation::isFinished() const
     return m_finished;
 }
 
-int ArenaSimulation::winnerTeam() const
+int ArenaSimulation::getWinnerTeam() const
 {
     return m_winnerTeam;
 }
 
-Tick ArenaSimulation::currentTick() const
+Tick ArenaSimulation::getCurrentTick() const
 {
     return m_currentTick;
 }
 
-const ArenaConfig& ArenaSimulation::arenaConfig() const
+const ArenaConfig& ArenaSimulation::getArenaConfig() const
 {
     return m_arenaConfig;
 }
 
-const BuildingSystem& ArenaSimulation::buildings() const
+const BuildingSystem& ArenaSimulation::getBuildings() const
 {
     return *m_buildingSystem;
 }
 
-const ShipSystem& ArenaSimulation::ships() const
+const ShipSystem& ArenaSimulation::getShips() const
 {
     return *m_shipSystem;
 }
 
-const ScrapSystem& ArenaSimulation::scraps() const
+const ScrapSystem& ArenaSimulation::getScraps() const
 {
     return *m_scrapSystem;
 }
 
-EntityAdmin& ArenaSimulation::admin()
+EntityAdmin& ArenaSimulation::getAdmin()
 {
     return m_admin;
 }
 
-const EntityAdmin& ArenaSimulation::admin() const
+const EntityAdmin& ArenaSimulation::getAdmin() const
 {
     return m_admin;
 }

src/balancing/ArenaSimulation.h

@@ -46,14 +46,14 @@ struct ArenaStatus
         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.
+        // baseline. See getEhpPercentText() 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;
+        std::string getEhpPercentText() const;
     };
 
     TeamStatus teams[2];
@@ -78,17 +78,17 @@ public:
     void tickOnce();
     std::vector<BeamFiredEvent> drainBeamFiredEvents();
 
-    ArenaStatus status() const;
+    ArenaStatus getStatus() const;
     bool isFinished() const;
-    int winnerTeam() const;
-    Tick currentTick() const;
+    int getWinnerTeam() const;
+    Tick getCurrentTick() const;
 
-    const ArenaConfig& arenaConfig() const;
-    const BuildingSystem& buildings() const;
-    const ShipSystem& ships() const;
-    const ScrapSystem& scraps() const;
-    EntityAdmin&       admin();
-    const EntityAdmin& admin() const;
+    const ArenaConfig& getArenaConfig() const;
+    const BuildingSystem& getBuildings() const;
+    const ShipSystem& getShips() const;
+    const ScrapSystem& getScraps() const;
+    EntityAdmin&       getAdmin();
+    const EntityAdmin& getAdmin() const;
 
 private:
     BuildingId allocateBuildingId();

src/balancing/ArenaView.cpp

@@ -73,7 +73,7 @@ void ArenaView::setGameSpeed(double multiplier)
         std::make_shared<GameSpeedChangedEvent>(multiplier));
 }
 
-double ArenaView::gameSpeed() const
+double ArenaView::getGameSpeed() const
 {
     return m_gameSpeedMultiplier;
 }
@@ -121,7 +121,7 @@ void ArenaView::onFrame()
     // Expire old beams. Lifetime is measured in game ticks so beams stay
     // visible while the simulation is paused or slowed (REQ-SHP-FIRING-BEAM).
     {
-        const Tick now = m_sim->currentTick();
+        const Tick now = m_sim->getCurrentTick();
         std::vector<ActiveBeam> live;
         for (const ActiveBeam& b : m_activeBeams)
         {
@@ -144,16 +144,16 @@ void ArenaView::onFrame()
 void ArenaView::handleEvent(std::shared_ptr<const BeamFiredEvent> event)
 {
     float maxRadius = 0.125f;
-    if (m_sim->admin().isValid(event->target)
-        && m_sim->admin().hasAll<StationBodyComponent>(event->target))
+    if (m_sim->getAdmin().isValid(event->target)
+        && m_sim->getAdmin().hasAll<StationBodyComponent>(event->target))
     {
-        const StationBodyComponent& sb = m_sim->admin().get<StationBodyComponent>(event->target);
+        const StationBodyComponent& sb = m_sim->getAdmin().get<StationBodyComponent>(event->target);
         const int shorter = std::min(sb.footprint.width(),
                                      sb.footprint.height());
         maxRadius = shorter / 2.0f;
     }
-    else if (m_sim->admin().isValid(event->target)
-        && m_sim->admin().hasAll<ScrapDataComponent>(event->target))
+    else if (m_sim->getAdmin().isValid(event->target)
+        && m_sim->getAdmin().hasAll<ScrapDataComponent>(event->target))
     {
         maxRadius = 0.1f;
     }
@@ -192,9 +192,9 @@ void ArenaView::paintGL()
 // Coordinate helpers
 // ---------------------------------------------------------------------------
 
-float ArenaView::tilePx() const
+float ArenaView::getTilePx() const
 {
-    const ArenaConfig& ac = m_sim->arenaConfig();
+    const ArenaConfig& ac = m_sim->getArenaConfig();
     const int totalWidth = ac.playerBufferWidth_tiles
                          + ac.contestZoneWidth_tiles
                          + ac.enemyBufferWidth_tiles;
@@ -209,8 +209,8 @@ float ArenaView::tilePx() const
 QPointF ArenaView::worldToWidget(QVector2D worldPos) const
 {
     return QPointF(
-        static_cast<qreal>(worldPos.x() * tilePx()),
-        static_cast<qreal>(worldPos.y() * tilePx()));
+        static_cast<qreal>(worldPos.x() * getTilePx()),
+        static_cast<qreal>(worldPos.y() * getTilePx()));
 }
 
 QPointF ArenaView::tileToWidget(QPoint tile) const
@@ -223,21 +223,21 @@ QRectF ArenaView::tileRect(QPoint tile) const
 {
     const QPointF tl = tileToWidget(tile);
     return QRectF(tl.x(), tl.y(),
-                  static_cast<qreal>(tilePx()), static_cast<qreal>(tilePx()));
+                  static_cast<qreal>(getTilePx()), static_cast<qreal>(getTilePx()));
 }
 
 std::optional<QVector2D> ArenaView::entityPosition(entt::entity entity) const
 {
-    if (!m_sim->admin().isValid(entity) || !m_sim->admin().hasAll<PositionComponent>(entity))
+    if (!m_sim->getAdmin().isValid(entity) || !m_sim->getAdmin().hasAll<PositionComponent>(entity))
     {
         return std::nullopt;
     }
-    return m_sim->admin().get<PositionComponent>(entity).value;
+    return m_sim->getAdmin().get<PositionComponent>(entity).value;
 }
 
 QVector2D ArenaView::widgetToWorld(QPoint widgetPt) const
 {
-    const float px = tilePx();
+    const float px = getTilePx();
     if (px < 0.001f) { return QVector2D(0.0f, 0.0f); }
     return QVector2D(static_cast<float>(widgetPt.x()) / px,
                      static_cast<float>(widgetPt.y()) / px);
@@ -248,7 +248,7 @@ void ArenaView::mousePressEvent(QMouseEvent* event)
     if (event->button() == Qt::LeftButton)
     {
         const QVector2D worldPos = widgetToWorld(event->pos());
-        entt::entity hit = entityAtWorldPos(m_sim->admin(), worldPos);
+        entt::entity hit = entityAtWorldPos(m_sim->getAdmin(), worldPos);
 
         if (hit != entt::null)
         {
@@ -282,7 +282,7 @@ void ArenaView::keyPressEvent(QKeyEvent* event)
 
 void ArenaView::drawTiles(QPainter& painter)
 {
-    const ArenaConfig& ac = m_sim->arenaConfig();
+    const ArenaConfig& ac = m_sim->getArenaConfig();
     const int totalWidth = ac.playerBufferWidth_tiles
                          + ac.contestZoneWidth_tiles
                          + ac.enemyBufferWidth_tiles;
@@ -300,7 +300,7 @@ void ArenaView::drawTiles(QPainter& painter)
 
 void ArenaView::drawBuildings(QPainter& painter)
 {
-    for (const Building& b : m_sim->buildings().allBuildings())
+    for (const Building& b : m_sim->getBuildings().getAllBuildings())
     {
         const std::map<BuildingType, BuildingVisuals>::const_iterator it =
             m_visuals->buildings.find(b.type);
@@ -315,8 +315,8 @@ void ArenaView::drawBuildings(QPainter& painter)
 
         const QPointF tl = tileToWidget(b.anchor);
         const QRectF bboxRect(tl.x(), tl.y(),
-            b.footprint.width()  * static_cast<qreal>(tilePx()),
-            b.footprint.height() * static_cast<qreal>(tilePx()));
+            b.footprint.width()  * static_cast<qreal>(getTilePx()),
+            b.footprint.height() * static_cast<qreal>(getTilePx()));
 
         painter.setPen(QPen(bv.outline, 1));
         painter.setBrush(Qt::NoBrush);
@@ -332,8 +332,8 @@ void ArenaView::drawBuildings(QPainter& painter)
 
 void ArenaView::drawScrap(QPainter& painter)
 {
-    const float r = tilePx() * 0.2f;
-    for (const ScrapInfo& scrap : m_sim->scraps().allScrapInfo())
+    const float r = getTilePx() * 0.2f;
+    for (const ScrapInfo& scrap : m_sim->getScraps().getAllScrapInfo())
     {
         const QPointF center = worldToWidget(scrap.position);
         painter.setBrush(QColor(128, 110, 90));
@@ -345,7 +345,7 @@ void ArenaView::drawScrap(QPainter& painter)
 
 void ArenaView::drawStations(QPainter& painter)
 {
-    m_sim->admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    m_sim->getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [&](entt::entity e, const StationBodyComponent& sb, const FactionComponent& f, const HealthComponent& h)
         {
             const BuildingType visType = f.isEnemy
@@ -364,8 +364,8 @@ void ArenaView::drawStations(QPainter& painter)
 
             const QPointF tl = tileToWidget(sb.anchor);
             const QRectF bboxRect(tl.x(), tl.y(),
-                sb.footprint.width()  * static_cast<qreal>(tilePx()),
-                sb.footprint.height() * static_cast<qreal>(tilePx()));
+                sb.footprint.width()  * static_cast<qreal>(getTilePx()),
+                sb.footprint.height() * static_cast<qreal>(getTilePx()));
 
             painter.setPen(QPen(bv.outline, 1));
             painter.setBrush(Qt::NoBrush);
@@ -374,7 +374,7 @@ void ArenaView::drawStations(QPainter& painter)
             if (h.maxHp > 0.0f)
             {
                 const float fraction = std::max(0.0f, h.hp / h.maxHp);
-                const qreal barH  = static_cast<qreal>(tilePx()) * 0.12;
+                const qreal barH  = static_cast<qreal>(getTilePx()) * 0.12;
                 const qreal barY  = bboxRect.bottom() + 1.0;
                 const qreal barW  = bboxRect.width();
                 painter.fillRect(QRectF(bboxRect.left(), barY, barW, barH),
@@ -394,7 +394,7 @@ void ArenaView::drawStations(QPainter& painter)
 
 void ArenaView::drawShips(QPainter& painter)
 {
-    m_sim->admin().forEach<ShipIdentityComponent, PositionComponent, FacingComponent,
+    m_sim->getAdmin().forEach<ShipIdentityComponent, PositionComponent, FacingComponent,
                            FactionComponent, HealthComponent>(
         [&](entt::entity e, const ShipIdentityComponent& si,
             const PositionComponent& pos, const FacingComponent& facing,
@@ -408,8 +408,8 @@ void ArenaView::drawShips(QPainter& painter)
 			const QVector2D dir(std::cos(facing.radians), std::sin(facing.radians));
             const QVector2D perp(-dir.y(), dir.x());
 
-            const float fwd  = tilePx() * 0.45f;
-            const float side = tilePx() * 0.25f;
+            const float fwd  = getTilePx() * 0.45f;
+            const float side = getTilePx() * 0.25f;
 
             QPolygonF tri;
             tri << QPointF(center.x() + static_cast<qreal>(dir.x()  * fwd),
@@ -427,7 +427,7 @@ void ArenaView::drawShips(QPainter& painter)
             {
                 const float fraction = std::max(0.0f, h.hp / h.maxHp);
                 const qreal barW = static_cast<qreal>(fwd) * 2.0;
-                const qreal barH = static_cast<qreal>(tilePx()) * 0.12;
+                const qreal barH = static_cast<qreal>(getTilePx()) * 0.12;
                 const qreal barX = center.x() - static_cast<qreal>(fwd);
                 const qreal barY = center.y() + static_cast<qreal>(fwd) + 1.0;
                 painter.fillRect(QRectF(barX, barY, barW, barH), QColor(60, 60, 60));
@@ -437,7 +437,7 @@ void ArenaView::drawShips(QPainter& painter)
 
             if (m_selectedEntity.has_value() && *m_selectedEntity == e)
             {
-                const qreal radius = static_cast<qreal>(tilePx()) * 0.55;
+                const qreal radius = static_cast<qreal>(getTilePx()) * 0.55;
                 painter.setPen(QPen(QColor(255, 255, 0), 2));
                 painter.setBrush(Qt::NoBrush);
                 painter.drawEllipse(center, radius, radius);
@@ -448,7 +448,7 @@ void ArenaView::drawShips(QPainter& painter)
 void ArenaView::drawDebugSensorRanges(QPainter& painter)
 {
     painter.setBrush(Qt::NoBrush);
-    m_sim->admin().forEach<ShipIdentityComponent, PositionComponent, SensorRangeComponent>(
+    m_sim->getAdmin().forEach<ShipIdentityComponent, PositionComponent, SensorRangeComponent>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& si,
             const PositionComponent& pos, const SensorRangeComponent& sensor)
         {
@@ -458,7 +458,7 @@ void ArenaView::drawDebugSensorRanges(QPainter& painter)
 
             const QPointF center   = worldToWidget(pos.value);
             const qreal   radiusPx = static_cast<qreal>(sensor.value_tiles)
-                                     * static_cast<qreal>(tilePx());
+                                     * static_cast<qreal>(getTilePx());
             QColor circleColor = it->second.outline;
             circleColor.setAlpha(77);
             painter.setPen(QPen(circleColor, 1));
@@ -487,7 +487,7 @@ void ArenaView::drawDebugTargetLines(QPainter& painter)
         painter.drawLine(worldToWidget(from), worldToWidget(to));
     };
 
-    m_sim->admin().forEach<ShipIdentityComponent, PositionComponent,
+    m_sim->getAdmin().forEach<ShipIdentityComponent, PositionComponent,
                            FactionComponent, AttackBehavior>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
             const PositionComponent& pos, const FactionComponent& fac,
@@ -502,7 +502,7 @@ void ArenaView::drawDebugTargetLines(QPainter& painter)
             drawTargetLine(fac.isEnemy, pos.value, *targetPos);
         });
 
-    m_sim->admin().forEach<ShipIdentityComponent, PositionComponent,
+    m_sim->getAdmin().forEach<ShipIdentityComponent, PositionComponent,
                            FactionComponent, RepairBehavior>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
             const PositionComponent& pos, const FactionComponent& fac,
@@ -517,7 +517,7 @@ void ArenaView::drawDebugTargetLines(QPainter& painter)
             drawTargetLine(fac.isEnemy, pos.value, *targetPos);
         });
 
-    m_sim->admin().forEach<ShipIdentityComponent, PositionComponent,
+    m_sim->getAdmin().forEach<ShipIdentityComponent, PositionComponent,
                            FactionComponent, SalvageScrapBehavior>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
             const PositionComponent& pos, const FactionComponent& fac,

src/balancing/ArenaView.h

@@ -32,7 +32,7 @@ public:
     ~ArenaView() override;
 
     void setGameSpeed(double multiplier);
-    double gameSpeed() const;
+    double getGameSpeed() const;
     void togglePause();
     void stopRendering();
 
@@ -56,7 +56,7 @@ private:
     void drawDebugTargetLines(QPainter& painter);
     void drawBeams(QPainter& painter);
 
-    float tilePx() const;
+    float getTilePx() const;
     QPointF worldToWidget(QVector2D worldPos) const;
     QPointF tileToWidget(QPoint tile) const;
     QRectF tileRect(QPoint tile) const;

src/balancing/ArenaWidget.cpp

@@ -141,7 +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())));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.getEhpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)

src/balancing/BalancingWindow.cpp

@@ -46,7 +46,7 @@ namespace
             header = QStringLiteral("[WON] ") + header;
         }
         header += QStringLiteral(" - threat %1").arg(QString::number(team.threatLevel, 'f', 0));
-        header += QStringLiteral(" - EHP %1").arg(QString::fromStdString(team.ehpPercentText()));
+        header += QStringLiteral(" - EHP %1").arg(QString::fromStdString(team.getEhpPercentText()));
         return escapeCell(header);
     }
 
@@ -147,7 +147,7 @@ void BalancingWindow::populateArenas(const BalancingConfig& balancingConfig)
         entry.widget = new ArenaWidget(index, arenaConfig.name, scrollContent);
         contentLayout->addWidget(entry.widget);
 
-        entry.widget->updateStatus(entry.simulation->status());
+        entry.widget->updateStatus(entry.simulation->getStatus());
 
         m_arenas.push_back(std::move(entry));
     }
@@ -179,14 +179,14 @@ void BalancingWindow::pollStatuses()
     {
         if (entry.worker.joinable())
         {
-            const ArenaStatus status = entry.simulation->status();
+            const ArenaStatus status = entry.simulation->getStatus();
             entry.widget->updateStatus(status);
         }
     }
 
     if (m_inspectedSim && m_inspectedArenaIndex >= 0)
     {
-        const ArenaStatus status = m_inspectedSim->status();
+        const ArenaStatus status = m_inspectedSim->getStatus();
         m_arenas[static_cast<std::size_t>(m_inspectedArenaIndex)].widget->updateStatus(status);
     }
 
@@ -242,7 +242,7 @@ void BalancingWindow::startArena(int index)
     entry.simulation = std::make_unique<ArenaSimulation>(
         m_gameConfig, entry.config, m_nextSeed++);
     entry.widget->startSimulation();
-    entry.widget->updateStatus(entry.simulation->status());
+    entry.widget->updateStatus(entry.simulation->getStatus());
     ArenaSimulation* sim = entry.simulation.get();
     entry.worker = std::thread([sim]() { sim->run(); });
     updateButtons();
@@ -278,7 +278,7 @@ void BalancingWindow::inspectArena(int index)
 
     entry.widget->resetToGrey();
     entry.widget->startSimulation();
-    entry.widget->updateStatus(m_inspectedSim->status());
+    entry.widget->updateStatus(m_inspectedSim->getStatus());
 
     m_inspectWindow = new InspectWindow(
         m_inspectedSim.get(), &m_gameConfig, &m_visuals, entry.config.name, nullptr);
@@ -336,7 +336,7 @@ void BalancingWindow::updateButtons()
     bool allRunning = true;
     for (ArenaEntry& entry : m_arenas)
     {
-        if (entry.worker.joinable() && !entry.simulation->status().finished)
+        if (entry.worker.joinable() && !entry.simulation->getStatus().finished)
         {
             anyRunning = true;
         }

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"
@@ -198,7 +199,7 @@ void InspectWindow::handleEvent(std::shared_ptr<const GameSpeedChangedEvent> eve
 
 void InspectWindow::pollStatus()
 {
-    const ArenaStatus status = m_sim->status();
+    const ArenaStatus status = m_sim->getStatus();
     updateInfoPanel(status);
     refreshEntityStats();
 }
@@ -227,7 +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())));
+        ehp->setText(tr("EHP: %1").arg(QString::fromStdString(team.getEhpPercentText())));
 
         QString lines;
         for (const ArenaStatus::Entry& entry : team.entries)
@@ -255,7 +256,7 @@ void InspectWindow::handleEvent(std::shared_ptr<const EntitySelectedEvent> event
     {
         m_selectedEntity = event->entity;
 
-        EntityAdmin& admin = m_sim->admin();
+        EntityAdmin& admin = m_sim->getAdmin();
         entt::entity entity = *m_selectedEntity;
 
         if (!admin.isValid(entity))
@@ -278,6 +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();
         }
@@ -329,7 +332,7 @@ void InspectWindow::refreshEntityStats()
 {
     if (!m_selectedEntity.has_value()) { return; }
 
-    EntityAdmin& admin = m_sim->admin();
+    EntityAdmin& admin = m_sim->getAdmin();
     entt::entity entity = *m_selectedEntity;
 
     if (!admin.isValid(entity))
@@ -355,6 +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/lib/config/BuildingsConfig.h

@@ -23,9 +23,26 @@ struct BuildingDef
     // 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

@@ -273,6 +273,18 @@ 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;
+    }
+
+    if (const std::optional<std::string> tip =
+            tbl["world"]["artifact_tooltip"].value<std::string>())
+    {
+        cfg.artifactTooltip = *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"));
@@ -343,6 +355,11 @@ BuildingsConfig ConfigLoader::loadBuildings(const std::string& path)
                 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)
         {
@@ -603,6 +620,11 @@ ModulesConfig ConfigLoader::loadModules(const std::string& path)
         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");

src/lib/config/Formula.h

@@ -30,7 +30,7 @@ public:
     // Evaluates the expression at the given x. Requires a compiled formula.
     double evaluate(double x) const;
 
-    const std::string& source() const { return m_source; }
+    const std::string& getSource() const { return m_source; }
     bool isValid() const { return m_expr != nullptr; }
 
 private:

src/lib/config/ModulesConfig.h

@@ -54,6 +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/WorldConfig.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include <optional>
+#include <string>
+
 #include "Formula.h"
 
 // Region widths are in tiles (REQ-GW-REGIONS).
@@ -75,6 +78,14 @@ 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;
+
+    // Optional hover-tooltip for the header artifact count display
+    // (REQ-UI-ARTIFACTS-TOOLTIP). Presentation-only; the simulation ignores it.
+    std::optional<std::string> artifactTooltip;
+
     WorldRegions regions;
     WorldExpansion expansion;
     WorldPush push;

src/lib/ecs/system/SalvagerSystem.cpp

@@ -30,7 +30,7 @@ void SalvagerSystem::tick(Tick currentTick, ScrapSystem& scraps, BuildingSystem&
     // Apply collections whose mid-beam delay has elapsed (cycles started earlier).
     applyPendingCollections(currentTick, scraps);
 
-    const std::vector<ScrapInfo> allScrap = scraps.allScrapInfo();
+    const std::vector<ScrapInfo> allScrap = scraps.getAllScrapInfo();
 
     // Tick down per-module collection cooldowns.
     m_admin.forEach<SalvagerComponent>(

src/lib/ecs/system/ScrapSystem.cpp

@@ -65,13 +65,13 @@ bool ScrapSystem::collectOne(entt::entity entity)
     return true;
 }
 
-std::vector<ScrapInfo> ScrapSystem::allScrapInfo() const
+std::vector<ScrapInfo> ScrapSystem::getAllScrapInfo() 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
@@ -34,7 +35,7 @@ public:
     bool collectOne(entt::entity entity);
 
     // Lightweight snapshot for callers that need to iterate all scrap.
-    std::vector<ScrapInfo> allScrapInfo() const;
+    std::vector<ScrapInfo> getAllScrapInfo() const;
 
 private:
     EntityAdmin& m_admin;

src/lib/ecs/system/ai/SalvageScrapEvaluator.cpp

@@ -19,7 +19,7 @@ void SalvageScrapEvaluator::evaluate(EntityAdmin& admin, const ScrapSystem& scra
 {
     TRACE();
     const std::unordered_map<entt::entity, CargoState> cargoByShip = buildCargoByShip(admin);
-    const std::vector<ScrapInfo> allScrap = scraps.allScrapInfo();
+    const std::vector<ScrapInfo> allScrap = scraps.getAllScrapInfo();
 
     admin.forEach<SalvageScrapBehavior, PositionComponent, SensorRangeComponent>(
         [&](entt::entity e, SalvageScrapBehavior& salvage, const PositionComponent& pos,

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/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 getOutputItemCount() 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

@@ -1,14 +1,59 @@
 #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.getBuildings().findBuilding(id);
+    const ConstructionSite* site     = building ? nullptr : sim.getBuildings().findSite(id);
+    if (!building && !site)
+    {
+        return std::nullopt;
+    }
+
+    const BuildingType  type = building ? building->type : site->type;
+    const BuildingDef*  def  = sim.getConfig().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);
+    const Building*         building = sim.getBuildings().findBuilding(id);
+    const ConstructionSite* site     = building ? nullptr : sim.getBuildings().findSite(id);
     if (!building && !site)
     {
         return std::nullopt;
@@ -32,7 +77,7 @@ std::optional<BuildingConfig> readBuildingConfig(const Simulation& sim, Building
         {
             // Operational splitter filters live in the BeltSystem, keyed by tile.
             const std::optional<BeltSystem::SplitterInfo> info =
-                sim.belts().getSplitterInfo(building->anchor);
+                sim.getBelts().getSplitterInfo(building->anchor);
             if (info.has_value())
             {
                 config.splitterFilterA = info->filterA;
@@ -49,3 +94,74 @@ std::optional<BuildingConfig> readBuildingConfig(const Simulation& sim, Building
 
     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

@@ -4,6 +4,7 @@
 #include <string>
 #include <vector>
 
+#include "Blueprint.h"
 #include "BuildingId.h"
 #include "BuildingType.h"
 #include "ItemType.h"
@@ -38,3 +39,16 @@ struct BuildingConfig
 // 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,
@@ -118,6 +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();
@@ -419,6 +521,12 @@ 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)
@@ -436,6 +544,12 @@ 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)
@@ -448,6 +562,12 @@ void BuildingSystem::setRecipe(BuildingId id, const std::string& recipeId)
             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())
@@ -494,6 +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);
@@ -597,12 +719,20 @@ 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.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)
@@ -664,79 +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();
@@ -752,18 +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)
@@ -779,66 +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.getOutputItemCount()
+                              + 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.
+        }
     }
 }
 
@@ -953,31 +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
 // ---------------------------------------------------------------------------
@@ -994,6 +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)
@@ -1006,12 +1279,12 @@ const ConstructionSite* BuildingSystem::findSite(BuildingId id) const
     return nullptr;
 }
 
-std::vector<Building> BuildingSystem::allBuildings() const
+std::vector<Building> BuildingSystem::getAllBuildings() const
 {
     return m_buildings;
 }
 
-std::vector<ConstructionSite> BuildingSystem::allSites() const
+std::vector<ConstructionSite> BuildingSystem::getAllSites() const
 {
     return std::vector<ConstructionSite>(m_constructionQueue.begin(),
                                          m_constructionQueue.end());
@@ -1035,7 +1308,7 @@ bool isProductionBuildingType(BuildingType type)
 }
 }  // namespace
 
-int BuildingSystem::productionBuildingCount() const
+int BuildingSystem::getProductionBuildingCount() const
 {
     int count = 0;
     for (const Building& b : m_buildings)
@@ -1045,7 +1318,7 @@ int BuildingSystem::productionBuildingCount() const
     return count;
 }
 
-int BuildingSystem::activeProductionBuildingCount() const
+int BuildingSystem::getActiveProductionBuildingCount() const
 {
     int count = 0;
     for (const Building& b : m_buildings)
@@ -1055,7 +1328,7 @@ int BuildingSystem::activeProductionBuildingCount() const
     return count;
 }
 
-std::vector<BuildingSystem::BeltTileInfo> BuildingSystem::allBeltTiles() const
+std::vector<BuildingSystem::BeltTileInfo> BuildingSystem::getAllBeltTiles() const
 {
     std::vector<BeltTileInfo> result;
     for (const Building& b : m_buildings)
@@ -1167,7 +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)
@@ -1236,7 +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->getOutputItemCount() >= bay->outputBuffer.capacity)
     {
         return false;
     }
@@ -1271,7 +1553,9 @@ 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)
     {
@@ -1377,6 +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"
@@ -94,7 +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
@@ -108,19 +112,32 @@ public:
 
     const Building*           findBuilding(BuildingId id)  const;
     const ConstructionSite*   findSite(BuildingId id)      const;
-    std::vector<Building>     allBuildings()             const;
-    std::vector<ConstructionSite> allSites()             const;
+    std::vector<Building>     getAllBuildings()             const;
+    std::vector<ConstructionSite> getAllSites()             const;
 
     // REQ-UI-DEBUG-OVERLAY "Max Factory Production": count of completed
     // (operational) Miner/Smelter/Assembler/ReprocessingPlant/Shipyard buildings.
-    int productionBuildingCount() const;
+    int getProductionBuildingCount() const;
 
     // REQ-UI-DEBUG-OVERLAY "Current Factory Production": subset of the above
     // that currently has an active production cycle.
-    int activeProductionBuildingCount() const;
-    std::vector<BeltTileInfo> allBeltTiles()             const;
+    int getActiveProductionBuildingCount() const;
+    std::vector<BeltTileInfo> getAllBeltTiles()             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.
@@ -164,11 +181,34 @@ 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;

src/lib/sim/CMakeLists.txt

@@ -8,6 +8,7 @@ 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
@@ -31,6 +32,7 @@ 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

src/lib/sim/CommandManager.cpp

@@ -46,18 +46,18 @@ void CommandManager::drain()
             {
                 // Restart is a file boundary: a fresh file with the new seed.
                 m_recorder->startNewRun(m_simulation.getSeed(),
-                                        m_simulation.rngFingerprint());
+                                        m_simulation.getRngFingerprint());
             }
         }
         else
         {
             // Commands drain before the tick batch, so currentTick is the count of
             // completed ticks the command is pinned to.
-            const Tick tick = m_simulation.currentTick();
+            const Tick tick = m_simulation.getCurrentTick();
             m_simulation.apply(*command);
             if (m_recorder)
             {
-                m_recorder->recordCommand(tick, *command, m_simulation.rngFingerprint());
+                m_recorder->recordCommand(tick, *command, m_simulation.getRngFingerprint());
             }
         }
     }
@@ -74,7 +74,7 @@ void CommandManager::setRecorder(std::unique_ptr<ReplayRecorder> recorder)
     m_recorder = std::move(recorder);
     if (m_recorder)
     {
-        m_recorder->startNewRun(m_simulation.getSeed(), m_simulation.rngFingerprint());
+        m_recorder->startNewRun(m_simulation.getSeed(), m_simulation.getRngFingerprint());
     }
 }
 
@@ -85,8 +85,8 @@ void CommandManager::setReplayMode(bool replayMode)
 
 void CommandManager::recordTickCheckpoint()
 {
-    if (m_recorder && (m_simulation.currentTick() % kChecksumIntervalTicks == 0))
+    if (m_recorder && (m_simulation.getCurrentTick() % kChecksumIntervalTicks == 0))
     {
-        m_recorder->recordChecksum(m_simulation.currentTick(), m_simulation.rngFingerprint());
+        m_recorder->recordChecksum(m_simulation.getCurrentTick(), m_simulation.getRngFingerprint());
     }
 }

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/ReplayPlayer.cpp

@@ -48,7 +48,7 @@ void ReplayPlayer::processEntriesAt(Tick tick)
         {
             m_simulation.apply(*entry.command);
         }
-        else if (m_simulation.rngFingerprint() != entry.fingerprint)
+        else if (m_simulation.getRngFingerprint() != entry.fingerprint)
         {
             m_desyncTick = tick;
         }

src/lib/sim/ReplayPlayer.h

@@ -19,7 +19,7 @@ class Simulation;
 //   each frame, for each tick to run:
 //       if (player.isFinished()) break;
 //       sim.tick();
-//       player.advanceTo(sim.currentTick());
+//       player.advanceTo(sim.getCurrentTick());
 class ReplayPlayer
 {
 public:

src/lib/sim/ReplayRecorder.cpp

@@ -58,7 +58,7 @@ std::string computeReplayConfigHash(const std::string& configDir)
             hasher.appendBytes(bytes.constData(), static_cast<std::size_t>(bytes.size()));
         }
     }
-    return toHex(hasher.value());
+    return toHex(hasher.getValue());
 }
 
 void ReplayRecorder::startNewRun(unsigned int seed, std::uint64_t initialRngFingerprint)
@@ -124,7 +124,7 @@ bool ReplayRecorder::isOpen() const
     return m_stream.is_open();
 }
 
-const std::string& ReplayRecorder::currentFilePath() const
+const std::string& ReplayRecorder::getCurrentFilePath() const
 {
     return m_filePath;
 }

src/lib/sim/ReplayRecorder.h

@@ -44,7 +44,7 @@ public:
 
     void close();
     bool isOpen() const;
-    const std::string& currentFilePath() const;
+    const std::string& getCurrentFilePath() const;
 
 private:
     std::string   m_configDir;

src/lib/sim/Simulation.cpp

@@ -113,7 +113,7 @@ Simulation::~Simulation()
 	unregisterForEvents();
 }
 
-const GameConfig& Simulation::config() const
+const GameConfig& Simulation::getConfig() const
 {
     return m_config;
 }
@@ -315,7 +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)
@@ -579,7 +579,7 @@ void Simulation::tickDeathsAndLoot()
         }
         else
         {
-            const double genD = static_cast<double>(m_waveSystem->generation());
+            const double genD = static_cast<double>(m_waveSystem->getGeneration());
             scrap = static_cast<int>(
                 m_config.stations.enemyStation.scrapDropFormula.evaluate(genD));
         }
@@ -619,9 +619,9 @@ void Simulation::tickDeathsAndLoot()
     if (es0Gone && es1Gone &&
         m_currentEnemyStationEntities[0] != entt::null)
     {
-        const int destroyedLevel = m_waveSystem->generation();
+        const int destroyedLevel = m_waveSystem->getGeneration();
         m_waveSystem->onEnemyStationsDestroyed();
-        placeEnemyStationSet(m_waveSystem->generation());
+        placeEnemyStationSet(m_waveSystem->getGeneration());
         generateSchematicChoices(destroyedLevel);
     }
 }
@@ -968,7 +968,7 @@ void Simulation::appendStringSet(Hasher& hasher, const std::set<std::string>& id
     }
 }
 
-unsigned long long Simulation::rngFingerprint() const
+unsigned long long Simulation::getRngFingerprint() const
 {
     return fingerprintRng(m_rng);
 }
@@ -991,11 +991,11 @@ unsigned long long Simulation::computeStateChecksum() const
     hasher.append(m_expansionsPurchased);
 
     // WaveSystem scalar state, reached through existing accessors.
-    hasher.append(threatLevel());
-    hasher.append(threatAccumulationRate());
-    hasher.append(bossWaveCounter());
-    hasher.append(bossCountdownTicks());
-    hasher.append(normalGapRemainingTicks());
+    hasher.append(getThreatLevel());
+    hasher.append(getThreatAccumulationRate());
+    hasher.append(getBossWaveCounter());
+    hasher.append(getBossCountdownTicks());
+    hasher.append(getNormalGapRemainingTicks());
 
     // Schematic / unlock state (std::map and std::set iterate in sorted order).
     appendSchematicMap(hasher, m_schematicLevels);
@@ -1052,7 +1052,7 @@ unsigned long long Simulation::computeStateChecksum() const
         hasher.append(c.schematicId);
     });
 
-    return hasher.value();
+    return hasher.getValue();
 }
 
 // ---------------------------------------------------------------------------
@@ -1081,7 +1081,7 @@ bool Simulation::hasSchematicChoicesPending() const
 // Accessors
 // ---------------------------------------------------------------------------
 
-Tick Simulation::currentTick() const
+Tick Simulation::getCurrentTick() const
 {
     return m_currentTick;
 }
@@ -1091,18 +1091,18 @@ unsigned int Simulation::getSeed() const
     return m_seed;
 }
 
-int Simulation::buildingBlocksStock() const
+int Simulation::getBuildingBlocksStock() const
 {
     return m_buildingBlocksStock;
 }
 
-int Simulation::currentAsteroidWidth_tiles() const
+int Simulation::getCurrentAsteroidWidth_tiles() const
 {
     return m_config.world.regions.asteroidWidth_tiles
         + m_expansionsPurchased * m_config.world.expansion.columnsPerExpansion_tiles;
 }
 
-int Simulation::currentExpansionCost() const
+int Simulation::getCurrentExpansionCost() const
 {
     const double cost = m_config.world.expansion.costBuildingBlocksFormula.evaluate(
         static_cast<double>(m_expansionsPurchased));
@@ -1111,14 +1111,14 @@ int Simulation::currentExpansionCost() const
 
 void Simulation::tryExpandAsteroid()
 {
-    const int cost = currentExpansionCost();
+    const int cost = getCurrentExpansionCost();
     if (m_buildingBlocksStock < cost)
     {
         return;
     }
     m_buildingBlocksStock -= cost;
     ++m_expansionsPurchased;
-    m_buildingSystem->setAsteroidWidth_tiles(currentAsteroidWidth_tiles());
+    m_buildingSystem->setAsteroidWidth_tiles(getCurrentAsteroidWidth_tiles());
 }
 
 bool Simulation::isGameOver() const
@@ -1131,44 +1131,44 @@ bool Simulation::isWon() const
     return m_isWon;
 }
 
-int Simulation::artifactCount() const
+int Simulation::getArtifactCount() const
 {
     return m_artifactCount;
 }
 
-double Simulation::threatLevel() const
+double Simulation::getThreatLevel() const
 {
-    return m_waveSystem->threatLevel();
+    return m_waveSystem->getThreatLevel();
 }
 
-double Simulation::threatAccumulationRate() const
+double Simulation::getThreatAccumulationRate() const
 {
-    return m_waveSystem->threatAccumulationRate();
+    return m_waveSystem->getThreatAccumulationRate();
 }
 
-double Simulation::maxFactoryProductionThreatRate() const
+double Simulation::getMaxFactoryProductionThreatRate() const
 {
-    return static_cast<double>(m_buildingSystem->productionBuildingCount());
+    return static_cast<double>(m_buildingSystem->getProductionBuildingCount());
 }
 
-double Simulation::currentFactoryProductionThreatRate() const
+double Simulation::getCurrentFactoryProductionThreatRate() const
 {
-    return static_cast<double>(m_buildingSystem->activeProductionBuildingCount());
+    return static_cast<double>(m_buildingSystem->getActiveProductionBuildingCount());
 }
 
-int Simulation::bossWaveCounter() const
+int Simulation::getBossWaveCounter() const
 {
-    return m_waveSystem->bossWaveCounter();
+    return m_waveSystem->getBossWaveCounter();
 }
 
-Tick Simulation::bossCountdownTicks() const
+Tick Simulation::getBossCountdownTicks() const
 {
-    return m_waveSystem->bossCountdownTicks();
+    return m_waveSystem->getBossCountdownTicks();
 }
 
-Tick Simulation::normalGapRemainingTicks() const
+Tick Simulation::getNormalGapRemainingTicks() const
 {
-    return m_waveSystem->normalGapRemainingTicks();
+    return m_waveSystem->getNormalGapRemainingTicks();
 }
 
 bool Simulation::isSchematicUnlocked(const std::string& shipId) const
@@ -1222,52 +1222,52 @@ void Simulation::demolish(BuildingId id)
     m_buildingBlocksStock += m_buildingSystem->demolish(id);
 }
 
-BuildingSystem& Simulation::buildingsMutable()
+BuildingSystem& Simulation::getBuildingsMutable()
 {
     return *m_buildingSystem;
 }
 
-const BuildingSystem& Simulation::buildings() const
+const BuildingSystem& Simulation::getBuildings() const
 {
     return *m_buildingSystem;
 }
 
-BeltSystem& Simulation::beltsMutable()
+BeltSystem& Simulation::getBeltsMutable()
 {
     return m_beltSystem;
 }
 
-const BeltSystem& Simulation::belts() const
+const BeltSystem& Simulation::getBelts() const
 {
     return m_beltSystem;
 }
 
-ShipSystem& Simulation::ships()
+ShipSystem& Simulation::getShips()
 {
     return *m_shipSystem;
 }
 
-const ShipSystem& Simulation::ships() const
+const ShipSystem& Simulation::getShips() const
 {
     return *m_shipSystem;
 }
 
-ScrapSystem& Simulation::scraps()
+ScrapSystem& Simulation::getScraps()
 {
     return *m_scrapSystem;
 }
 
-const ScrapSystem& Simulation::scraps() const
+const ScrapSystem& Simulation::getScraps() const
 {
     return *m_scrapSystem;
 }
 
-EntityAdmin& Simulation::admin()
+EntityAdmin& Simulation::getAdmin()
 {
     return m_admin;
 }
 
-const EntityAdmin& Simulation::admin() const
+const EntityAdmin& Simulation::getAdmin() const
 {
     return m_admin;
 }

src/lib/sim/Simulation.h

@@ -41,7 +41,7 @@ public:
     explicit Simulation(GameConfig config, unsigned int seed = 0);
     ~Simulation();
 
-    const GameConfig& config() const;
+    const GameConfig& getConfig() const;
 
     // Reinitializes all simulation state as if constructed fresh.
     void reset(unsigned int seed = 0);
@@ -68,26 +68,26 @@ public:
     // Returns true if there are pending schematic choices waiting for player input.
     bool hasSchematicChoicesPending() const;
 
-    Tick   currentTick()          const;
+    Tick   getCurrentTick()          const;
     // The seed this run was (re)initialized with; written to the replay header.
     unsigned int getSeed()        const;
-    int    buildingBlocksStock()  const;
+    int    getBuildingBlocksStock()  const;
     // Current asteroid width in tiles = base width + purchased expansions
     // (REQ-EXP-UNLOCK, REQ-GW-ASTEROID-EXPAND).
-    int    currentAsteroidWidth_tiles() const;
+    int    getCurrentAsteroidWidth_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;
+    int    getCurrentExpansionCost()  const;
     bool   isGameOver()           const;
     bool   isWon()                const;
-    int    artifactCount()        const;
-    double threatLevel()          const;
-    double threatAccumulationRate() const;
-    double maxFactoryProductionThreatRate()     const;
-    double currentFactoryProductionThreatRate() const;
-    int    bossWaveCounter()      const;
-    Tick   bossCountdownTicks()         const;
-    Tick   normalGapRemainingTicks()    const;
+    int    getArtifactCount()        const;
+    double getThreatLevel()          const;
+    double getThreatAccumulationRate() const;
+    double getMaxFactoryProductionThreatRate()     const;
+    double getCurrentFactoryProductionThreatRate() const;
+    int    getBossWaveCounter()      const;
+    Tick   getBossCountdownTicks()         const;
+    Tick   getNormalGapRemainingTicks()    const;
 
     // Ship schematic state query.
     bool isSchematicUnlocked(const std::string& shipId) const;
@@ -102,25 +102,25 @@ public:
     // -- Determinism (see docs/replay_design.md) -----------------------------
     // 64-bit fingerprint of the RNG stream state. Cheap; written to the replay
     // file periodically + after each command for desync detection.
-    unsigned long long rngFingerprint() const;
+    unsigned long long getRngFingerprint() const;
 
     // 64-bit fingerprint of the full simulation state (RNG, scalars, buildings,
     // belts, and ECS component state). Used by the double-run determinism test;
-    // a superset of rngFingerprint().
+    // a superset of getRngFingerprint().
     unsigned long long computeStateChecksum() const;
 
     // Const subsystem accessors (queries only). The mutable counterparts are
     // private and reachable only through Simulation::apply (the command
     // chokepoint) or, in tests, SimulationTestAccess — so production code cannot
     // mutate the factory outside the recorded command path (docs/replay_design.md).
-    const BuildingSystem& buildings() const;
-    const BeltSystem&     belts() const;
-    ShipSystem&           ships();
-    const ShipSystem&     ships() const;
-    ScrapSystem&          scraps();
-    const ScrapSystem&    scraps() const;
-    EntityAdmin&          admin();
-    const EntityAdmin&    admin() const;
+    const BuildingSystem& getBuildings() const;
+    const BeltSystem&     getBelts() const;
+    ShipSystem&           getShips();
+    const ShipSystem&     getShips() const;
+    ScrapSystem&          getScraps();
+    const ScrapSystem&    getScraps() const;
+    EntityAdmin&          getAdmin();
+    const EntityAdmin&    getAdmin() const;
 
 private:
     // Grants tests access to the private player-action mutators below without
@@ -148,8 +148,8 @@ private:
     void tryExpandAsteroid();
 
     // Mutable subsystem accessors; same chokepoint rule as the mutators above.
-    BuildingSystem&       buildingsMutable();
-    BeltSystem&           beltsMutable();
+    BuildingSystem&       getBuildingsMutable();
+    BeltSystem&           getBeltsMutable();
 
 	void handleEvent(std::shared_ptr<const TracePrintRequestedEvent> event) override;
 

src/lib/sim/StateChecksum.cpp

@@ -57,5 +57,5 @@ std::uint64_t fingerprintRng(const std::mt19937& rng)
     stream << rng;  // full internal state as space-separated integers
     Hasher hasher;
     hasher.append(stream.str());
-    return hasher.value();
+    return hasher.getValue();
 }

src/lib/sim/StateChecksum.h

@@ -43,7 +43,7 @@ public:
     void append(const QVector2D& vector);
     void append(const std::string& text);
 
-    std::uint64_t value() const { return m_state; }
+    std::uint64_t getValue() const { return m_state; }
 
 private:
     std::uint64_t m_state = 14695981039346656037ull;  // FNV-1a 64-bit offset basis

src/lib/sim/WaveSystem.cpp

@@ -98,12 +98,12 @@ void WaveSystem::onEnemyStationsDestroyed()
     ++m_generation;
 }
 
-double WaveSystem::threatLevel() const
+double WaveSystem::getThreatLevel() const
 {
     return m_threatLevel;
 }
 
-double WaveSystem::threatAccumulationRate() const
+double WaveSystem::getThreatAccumulationRate() const
 {
     if (isInQuietWindow())
     {
@@ -113,22 +113,22 @@ double WaveSystem::threatAccumulationRate() const
     return std::max(0.0, m_config.world.waves.threatRateFormula.evaluate(x));
 }
 
-int WaveSystem::generation() const
+int WaveSystem::getGeneration() const
 {
     return m_generation;
 }
 
-int WaveSystem::bossWaveCounter() const
+int WaveSystem::getBossWaveCounter() const
 {
     return m_bossWaveCounter;
 }
 
-Tick WaveSystem::bossCountdownTicks() const
+Tick WaveSystem::getBossCountdownTicks() const
 {
     return m_bossCountdownTicks;
 }
 
-Tick WaveSystem::normalGapRemainingTicks() const
+Tick WaveSystem::getNormalGapRemainingTicks() const
 {
     return m_normalGapRemainingTicks;
 }

src/lib/sim/WaveSystem.h

@@ -34,26 +34,26 @@ public:
     // (REQ-WAV-BOSS-ADVANCE, REQ-PSH-STATION-STATS).
     void onEnemyStationsDestroyed();
 
-    double threatLevel() const;
+    double getThreatLevel() const;
 
-    // Current rate at which threatLevel() is increasing, in threat/second
+    // Current rate at which getThreatLevel() is increasing, in threat/second
     // (REQ-WAV-THREAT-RATE). 0 during a quiet window (REQ-WAV-QUIET) or when
     // the rate formula evaluates to a negative value.
-    double threatAccumulationRate() const;
+    double getThreatAccumulationRate() const;
 
     // Current enemy-station generation level (0 for initial set,
     // incremented by 1 after each push — REQ-PSH-STATION-STATS).
-    int generation() const;
+    int getGeneration() const;
 
     // Boss wave counter (REQ-WAV-BOSS-COUNTER): current cycle number, starts at 1.
-    int bossWaveCounter() const;
+    int getBossWaveCounter() const;
 
     // Ticks remaining until the next boss wave fires (REQ-WAV-BOSS-COUNTDOWN).
-    Tick bossCountdownTicks() const;
+    Tick getBossCountdownTicks() const;
 
     // Ticks remaining on the current normal-wave gap timer (REQ-WAV-GAP).
     // Frozen during quiet windows.
-    Tick normalGapRemainingTicks() const;
+    Tick getNormalGapRemainingTicks() const;
 
 private:
     struct SpawnEntry

src/test/ArtifactWinConditionTest.cpp

@@ -19,7 +19,7 @@ static GameConfig loadConfig()
 
 static void killEnemyStations(Simulation& sim)
 {
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity, StationBodyComponent&, FactionComponent& faction, HealthComponent& health)
         {
             if (faction.isEnemy)
@@ -65,7 +65,7 @@ TEST_CASE("ArtifactWinCondition: artifact count is 0 and isWon is false at game
           "[artifact_win]")
 {
     const Simulation sim(loadConfig());
-    CHECK(sim.artifactCount() == 0);
+    CHECK(sim.getArtifactCount() == 0);
     CHECK_FALSE(sim.isWon());
 }
 
@@ -145,7 +145,7 @@ TEST_CASE("ArtifactWinCondition: selecting artifact increments artifact count",
 
     SimulationTestAccess::applySchematicChoice(sim,index);
 
-    CHECK(sim.artifactCount() == 1);
+    CHECK(sim.getArtifactCount() == 1);
 }
 
 TEST_CASE("ArtifactWinCondition: selecting a non-artifact option does not increment artifact count",
@@ -166,7 +166,7 @@ TEST_CASE("ArtifactWinCondition: selecting a non-artifact option does not increm
 
     SimulationTestAccess::applySchematicChoice(sim,static_cast<int>(it - choices.begin()));
 
-    CHECK(sim.artifactCount() == 0);
+    CHECK(sim.getArtifactCount() == 0);
 }
 
 // ---------------------------------------------------------------------------
@@ -205,7 +205,7 @@ TEST_CASE("ArtifactWinCondition: isWon stays false when artifact count is below
     REQUIRE(sim.hasSchematicChoicesPending());
     SimulationTestAccess::applySchematicChoice(sim,findArtifactChoiceIndex(sim));
 
-    CHECK(sim.artifactCount() == 1);
+    CHECK(sim.getArtifactCount() == 1);
     CHECK_FALSE(sim.isWon());
 }
 
@@ -226,7 +226,7 @@ TEST_CASE("ArtifactWinCondition: isWon becomes true after collecting required nu
         SimulationTestAccess::applySchematicChoice(sim,index);
     }
 
-    CHECK(sim.artifactCount() == 2);
+    CHECK(sim.getArtifactCount() == 2);
     CHECK(sim.isWon());
 }
 
@@ -249,6 +249,6 @@ TEST_CASE("ArtifactWinCondition: reset clears artifact count and win state",
 
     sim.reset();
 
-    CHECK(sim.artifactCount() == 0);
+    CHECK(sim.getArtifactCount() == 0);
     CHECK_FALSE(sim.isWon());
 }

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"
@@ -532,9 +533,9 @@ TEST_CASE("Blueprint placement: buildings land at anchor + offset from cursor",
 
     REQUIRE(idA != kInvalidBuildingId);
     REQUIRE(idB != kInvalidBuildingId);
-    REQUIRE(sim.buildings().isTileOccupied(cursor + offsetA));   // (-6, 0)
-    REQUIRE(sim.buildings().isTileOccupied(cursor + offsetB));   // (-4, 0)
-    REQUIRE_FALSE(sim.buildings().isTileOccupied(cursor));       // center not occupied
+    REQUIRE(sim.getBuildings().isTileOccupied(cursor + offsetA));   // (-6, 0)
+    REQUIRE(sim.getBuildings().isTileOccupied(cursor + offsetB));   // (-4, 0)
+    REQUIRE_FALSE(sim.getBuildings().isTileOccupied(cursor));       // center not occupied
 }
 
 TEST_CASE("Blueprint placement: cost is deducted for each building in sequence", "[blueprint]")
@@ -543,20 +544,20 @@ TEST_CASE("Blueprint placement: cost is deducted for each building in sequence",
 
     // Find belt cost from config (belt cost = 2 in test config).
     int beltCost = 0;
-    for (const BuildingDef& def : sim.config().buildings.buildings)
+    for (const BuildingDef& def : sim.getConfig().buildings.buildings)
     {
         if (def.type == BuildingType::Belt) { beltCost = def.cost; break; }
     }
     REQUIRE(beltCost > 0);
 
-    const int startBlocks = sim.buildingBlocksStock();
+    const int startBlocks = sim.getBuildingBlocksStock();
     REQUIRE(startBlocks >= 2 * beltCost);   // test config has enough starting blocks
 
     SimulationTestAccess::place(sim,BuildingType::Belt, QPoint(-6, 0), Rotation::East);
-    REQUIRE(sim.buildingBlocksStock() == startBlocks - beltCost);
+    REQUIRE(sim.getBuildingBlocksStock() == startBlocks - beltCost);
 
     SimulationTestAccess::place(sim,BuildingType::Belt, QPoint(-4, 0), Rotation::East);
-    REQUIRE(sim.buildingBlocksStock() == startBlocks - 2 * beltCost);
+    REQUIRE(sim.getBuildingBlocksStock() == startBlocks - 2 * beltCost);
 }
 
 TEST_CASE("Blueprint placement: insufficient blocks returns kInvalidBuildingId and deducts nothing",
@@ -566,7 +567,7 @@ TEST_CASE("Blueprint placement: insufficient blocks returns kInvalidBuildingId a
 
     // Find miner cost (15 in test config) — expensive enough to exhaust a small stock.
     int minerCost = 0;
-    for (const BuildingDef& def : sim.config().buildings.buildings)
+    for (const BuildingDef& def : sim.getConfig().buildings.buildings)
     {
         if (def.type == BuildingType::Miner) { minerCost = def.cost; break; }
     }
@@ -575,26 +576,26 @@ TEST_CASE("Blueprint placement: insufficient blocks returns kInvalidBuildingId a
     // Drain the stock by placing miners until we no longer have enough.
     // Non-overlapping columns: miner body is 2 wide, so step by 2.
     int col = -2;
-    while (sim.buildingBlocksStock() >= minerCost)
+    while (sim.getBuildingBlocksStock() >= minerCost)
     {
         SimulationTestAccess::place(sim,BuildingType::Miner, QPoint(col, 0), Rotation::East);
         col -= 2;
     }
 
-    const int blocksBeforeAttempt = sim.buildingBlocksStock();
+    const int blocksBeforeAttempt = sim.getBuildingBlocksStock();
     const BuildingId id = SimulationTestAccess::place(sim,
         BuildingType::Miner, QPoint(col - 2, 0), Rotation::East);
 
     // Placement must fail and leave the stock unchanged.
     REQUIRE(id == kInvalidBuildingId);
-    REQUIRE(sim.buildingBlocksStock() == blocksBeforeAttempt);
+    REQUIRE(sim.getBuildingBlocksStock() == blocksBeforeAttempt);
 }
 
 TEST_CASE("Simulation: tryPlaceBuilding rejects terrain-invalid placement and charges nothing",
           "[blueprint]")
 {
     Simulation sim(loadConfig());
-    const int startBlocks = sim.buildingBlocksStock();
+    const int startBlocks = sim.getBuildingBlocksStock();
 
     // A miner is all-asteroid; placing it in space (x >= 0) violates the terrain
     // rule, so it must be rejected without consuming building blocks.
@@ -602,8 +603,8 @@ TEST_CASE("Simulation: tryPlaceBuilding rejects terrain-invalid placement and ch
         SimulationTestAccess::place(sim,BuildingType::Miner, QPoint(0, 0), Rotation::East);
 
     REQUIRE(id == kInvalidBuildingId);
-    REQUIRE(sim.buildingBlocksStock() == startBlocks);
-    REQUIRE(sim.buildings().allSites().empty());
+    REQUIRE(sim.getBuildingBlocksStock() == startBlocks);
+    REQUIRE(sim.getBuildings().getAllSites().empty());
 }
 
 TEST_CASE("Simulation: tryPlaceBuilding accepts a valid asteroid spot, occupies tiles, charges cost",
@@ -612,12 +613,12 @@ TEST_CASE("Simulation: tryPlaceBuilding accepts a valid asteroid spot, occupies
     Simulation sim(loadConfig());
 
     int minerCost = 0;
-    for (const BuildingDef& def : sim.config().buildings.buildings)
+    for (const BuildingDef& def : sim.getConfig().buildings.buildings)
     {
         if (def.type == BuildingType::Miner) { minerCost = def.cost; break; }
     }
     REQUIRE(minerCost > 0);
-    const int startBlocks = sim.buildingBlocksStock();
+    const int startBlocks = sim.getBuildingBlocksStock();
 
     // Miner mask ["AA","A>"] East at (-3,0) → all-asteroid body at
     // (-3,0),(-2,0),(-3,1); a valid spot.
@@ -625,12 +626,12 @@ TEST_CASE("Simulation: tryPlaceBuilding accepts a valid asteroid spot, occupies
         SimulationTestAccess::place(sim,BuildingType::Miner, QPoint(-3, 0), Rotation::East);
 
     REQUIRE(id != kInvalidBuildingId);
-    REQUIRE(sim.buildingBlocksStock() == startBlocks - minerCost);
-    REQUIRE(sim.buildings().isTileOccupied(QPoint(-3, 0)));
-    REQUIRE(sim.buildings().isTileOccupied(QPoint(-2, 0)));
-    REQUIRE(sim.buildings().isTileOccupied(QPoint(-3, 1)));
+    REQUIRE(sim.getBuildingBlocksStock() == startBlocks - minerCost);
+    REQUIRE(sim.getBuildings().isTileOccupied(QPoint(-3, 0)));
+    REQUIRE(sim.getBuildings().isTileOccupied(QPoint(-2, 0)));
+    REQUIRE(sim.getBuildings().isTileOccupied(QPoint(-3, 1)));
     // The output-port tile (1,1)+anchor = (-2,1) is not a body cell.
-    REQUIRE_FALSE(sim.buildings().isTileOccupied(QPoint(-2, 1)));
+    REQUIRE_FALSE(sim.getBuildings().isTileOccupied(QPoint(-2, 1)));
 }
 
 // ---------------------------------------------------------------------------
@@ -670,7 +671,7 @@ TEST_CASE("Blueprint placement: setRecipe on construction site stores recipe", "
 
     SimulationTestAccess::buildings(sim).setRecipe(id, "mine_iron_ore");
 
-    const ConstructionSite* site = sim.buildings().findSite(id);
+    const ConstructionSite* site = sim.getBuildings().findSite(id);
     REQUIRE(site != nullptr);
     REQUIRE(site->recipeId == "mine_iron_ore");
 }
@@ -691,11 +692,97 @@ TEST_CASE("Blueprint placement: recipe transfers to building after construction
         sim.tick();
     }
 
-    const Building* b = sim.buildings().findBuilding(id);
+    const Building* b = sim.getBuildings().findBuilding(id);
     REQUIRE(b != nullptr);
     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.getBuildings().findSite(id) != nullptr);
+    REQUIRE(sim.getBuildings().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.getBuildings().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.getBuildings().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.getBuildings().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.
@@ -772,7 +859,7 @@ TEST_CASE("Blueprint placement: setShipLayout on construction site stores layout
 
     SimulationTestAccess::buildings(sim).setShipLayout(id, layout);
 
-    const ConstructionSite* site = sim.buildings().findSite(id);
+    const ConstructionSite* site = sim.getBuildings().findSite(id);
     REQUIRE(site != nullptr);
     REQUIRE(site->shipLayout.has_value());
     REQUIRE(site->shipLayout->placedModules.size() == 1);
@@ -798,7 +885,7 @@ TEST_CASE("Blueprint placement: ship layout transfers to building after construc
 
     // Shipyard construction_time_seconds = 30 in the test config.
     double constructionTime = 0.0;
-    for (const BuildingDef& def : sim.config().buildings.buildings)
+    for (const BuildingDef& def : sim.getConfig().buildings.buildings)
     {
         if (def.type == BuildingType::Shipyard) { constructionTime = def.constructionTimeSeconds; break; }
     }
@@ -809,7 +896,7 @@ TEST_CASE("Blueprint placement: ship layout transfers to building after construc
         sim.tick();
     }
 
-    const Building* b = sim.buildings().findBuilding(id);
+    const Building* b = sim.getBuildings().findBuilding(id);
     REQUIRE(b != nullptr);
     REQUIRE(b->shipLayout.has_value());
     REQUIRE(b->shipLayout->placedModules.size() == 1);

src/test/BuildingConfigTest.cpp

@@ -114,8 +114,8 @@ TEST_CASE("readBuildingConfig reads a queued construction site", "[copyconfig]")
     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);
+    REQUIRE(sim.getBuildings().findBuilding(id) == nullptr);
+    REQUIRE(sim.getBuildings().findSite(id) != nullptr);
 
     SimulationTestAccess::buildings(sim).setRecipe(id, "mine_iron_ore");
 

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
 {
@@ -124,7 +140,7 @@ TEST_CASE("BuildingSystem: place rejects a building above the world (y < 0)", "[
     // row sits above the world.
     const BuildingId id = f.bs.place(BuildingType::Miner, QPoint(0, -1), Rotation::East, 0);
     REQUIRE(id == kInvalidBuildingId);
-    REQUIRE(f.bs.allSites().empty());
+    REQUIRE(f.bs.getAllSites().empty());
     REQUIRE_FALSE(f.bs.isTileOccupied(QPoint(0, 0)));
 }
 
@@ -138,7 +154,7 @@ TEST_CASE("BuildingSystem: place rejects a building below the world (y >= height
     const BuildingId id = f.bs.place(BuildingType::Miner,
                                      QPoint(0, heightTiles - 1), Rotation::East, 0);
     REQUIRE(id == kInvalidBuildingId);
-    REQUIRE(f.bs.allSites().empty());
+    REQUIRE(f.bs.getAllSites().empty());
 }
 
 TEST_CASE("BuildingSystem: place rejects a building left of the asteroid edge", "[building]")
@@ -149,7 +165,7 @@ TEST_CASE("BuildingSystem: place rejects a building left of the asteroid edge",
     const BuildingId id = f.bs.place(BuildingType::Miner,
                                      QPoint(leftEdgeX - 1, 0), Rotation::East, 0);
     REQUIRE(id == kInvalidBuildingId);
-    REQUIRE(f.bs.allSites().empty());
+    REQUIRE(f.bs.getAllSites().empty());
 }
 
 TEST_CASE("BuildingSystem: place accepts a building flush against the world's left edge",
@@ -214,16 +230,16 @@ 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(bs.allBuildings().size() == 1);
-    REQUIRE(bs.allBuildings()[0].type == BuildingType::Belt);
-    REQUIRE(bs.allBuildings()[0].anchor == QPoint(5, 5));
+    REQUIRE(belts.tryPutItem(QPoint(5, 5), makeItem("iron_ore"), Rotation::East));
+    REQUIRE(bs.getAllBuildings().size() == 1);
+    REQUIRE(bs.getAllBuildings()[0].type == BuildingType::Belt);
+    REQUIRE(bs.getAllBuildings()[0].anchor == QPoint(5, 5));
 }
 
 TEST_CASE("BuildingSystem: placed building enters construction queue", "[building]")
@@ -242,8 +258,8 @@ TEST_CASE("BuildingSystem: placed building enters construction queue", "[buildin
 
     const BuildingId id = bs.place(BuildingType::Miner, QPoint(0, 0), Rotation::East, 0);
 
-    REQUIRE(bs.allSites().size() == 1);
-    REQUIRE(bs.allBuildings().empty());
+    REQUIRE(bs.getAllSites().size() == 1);
+    REQUIRE(bs.getAllBuildings().empty());
     REQUIRE(bs.findSite(id) != nullptr);
 }
 
@@ -273,7 +289,7 @@ TEST_CASE("BuildingSystem: demolish frees tiles and returns refund", "[building]
     // Miner cost = 15, refund = floor(15 * 75 / 100) = 11.
     REQUIRE(refund == 15 * cfg.world.refundPercentage / 100);
     REQUIRE_FALSE(bs.isTileOccupied(QPoint(0, 0)));
-    REQUIRE(bs.allSites().empty());
+    REQUIRE(bs.getAllSites().empty());
 }
 
 // ---------------------------------------------------------------------------
@@ -296,7 +312,7 @@ TEST_CASE("BuildingSystem: first queued building starts construction immediately
                       rng);
 
     bs.place(BuildingType::Miner, QPoint(0, 0), Rotation::East, 0);
-    REQUIRE(bs.allSites().front().completesAt > 0);
+    REQUIRE(bs.getAllSites().front().completesAt > 0);
 }
 
 TEST_CASE("BuildingSystem: second queued building waits (completesAt == 0)", "[building]")
@@ -316,9 +332,9 @@ TEST_CASE("BuildingSystem: second queued building waits (completesAt == 0)", "[b
     bs.place(BuildingType::Miner, QPoint(0, 0), Rotation::East, 0);
     bs.place(BuildingType::Miner, QPoint(5, 5), Rotation::East, 0);
 
-    REQUIRE(bs.allSites().size() == 2);
-    REQUIRE(bs.allSites()[0].completesAt > 0);
-    REQUIRE(bs.allSites()[1].completesAt == 0);
+    REQUIRE(bs.getAllSites().size() == 2);
+    REQUIRE(bs.getAllSites()[0].completesAt > 0);
+    REQUIRE(bs.getAllSites()[1].completesAt == 0);
 }
 
 TEST_CASE("BuildingSystem: construction completes after configured duration", "[building]")
@@ -342,7 +358,7 @@ TEST_CASE("BuildingSystem: construction completes after configured duration", "[
     Tick tick = 0;
     runTicks(bs, belts, static_cast<int>(secondsToTicks(10.0)) + 1, tick);
 
-    REQUIRE(bs.allSites().empty());
+    REQUIRE(bs.getAllSites().empty());
     REQUIRE(bs.findBuilding(id) != nullptr);
 }
 
@@ -367,9 +383,9 @@ TEST_CASE("BuildingSystem: second building starts after first completes", "[buil
     Tick tick = 0;
     runTicks(bs, belts, static_cast<int>(secondsToTicks(10.0)) + 1, tick);
 
-    REQUIRE(bs.allSites().size() == 1);
-    REQUIRE(bs.allSites().front().id == id2);
-    REQUIRE(bs.allSites().front().completesAt > 0);
+    REQUIRE(bs.getAllSites().size() == 1);
+    REQUIRE(bs.getAllSites().front().id == id2);
+    REQUIRE(bs.getAllSites().front().completesAt > 0);
 }
 
 // ---------------------------------------------------------------------------
@@ -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->getOutputItemCount() == 2);
     REQUIRE_FALSE(b->production.has_value());
 }
 
@@ -464,22 +485,23 @@ TEST_CASE("BuildingSystem: productionBuildingCount excludes construction sites",
 
     Tick tick = 0;
     // Both still under construction.
-    REQUIRE(bs.productionBuildingCount() == 0);
+    REQUIRE(bs.getProductionBuildingCount() == 0);
 
     // The queue builds one at a time: miner (10s) completes at tick 300, then
     // the smelter (15s) starts and completes at tick 300 + 450 = 750.
     runTicks(bs, belts, static_cast<int>(secondsToTicks(10.0)) + 1, tick);
-    REQUIRE(bs.productionBuildingCount() == 1);
+    REQUIRE(bs.getProductionBuildingCount() == 1);
 
     runTicks(bs, belts, static_cast<int>(secondsToTicks(15.0)), tick);
-    REQUIRE(bs.productionBuildingCount() == 2);
+    REQUIRE(bs.getProductionBuildingCount() == 2);
 
-    // Neither has a recipe selected, so neither has an active cycle.
-    REQUIRE(bs.activeProductionBuildingCount() == 0);
+    // 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.getActiveProductionBuildingCount() == 0);
 
     bs.setRecipe(minerId, "mine_iron_ore");
     runTicks(bs, belts, 1, tick);
-    REQUIRE(bs.activeProductionBuildingCount() == 1);
+    REQUIRE(bs.getActiveProductionBuildingCount() == 1);
 }
 
 TEST_CASE("BuildingSystem: activeProductionBuildingCount tracks production cycle state",
@@ -502,11 +524,11 @@ TEST_CASE("BuildingSystem: activeProductionBuildingCount tracks production cycle
 
     Tick tick = 0;
     // Not yet operational while under construction.
-    REQUIRE(bs.activeProductionBuildingCount() == 0);
+    REQUIRE(bs.getActiveProductionBuildingCount() == 0);
 
     // Construction completes at tick 300; cycle 1 starts the same tick (completesAt=330).
     runTicks(bs, belts, static_cast<int>(secondsToTicks(10.0)) + 1, tick);
-    REQUIRE(bs.activeProductionBuildingCount() == 1);
+    REQUIRE(bs.getActiveProductionBuildingCount() == 1);
 
     // Run cycles 1 and 2 to completion (1s each); cycle 3 stalls once the
     // output buffer (capacity 2) is full (REQ-MAT-OUTPUT-BUFFER).
@@ -514,9 +536,9 @@ 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->getOutputItemCount() == 2);
     REQUIRE_FALSE(b->production.has_value());
-    REQUIRE(bs.activeProductionBuildingCount() == 0);
+    REQUIRE(bs.getActiveProductionBuildingCount() == 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->getOutputItemCount() == 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->getOutputItemCount() > 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->getOutputItemCount() == 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).
@@ -798,7 +1083,7 @@ TEST_CASE("BuildingSystem: findRotateInPlaceTarget returns the building id for a
 
     Tick tick = 0;
     runTicks(bs, belts, static_cast<int>(secondsToTicks(1.0)) + 1, tick);
-    REQUIRE(bs.allSites().empty());
+    REQUIRE(bs.getAllSites().empty());
 
     const std::optional<BuildingId> result =
         bs.findRotateInPlaceTarget(BuildingType::Belt, QPoint(0, 0), Rotation::South);
@@ -1010,12 +1295,12 @@ TEST_CASE("BuildingSystem: splitter filters configured on a construction site ca
 
     // Run until construction completes.
     Tick tick = 0;
-    while (f.bs.allBuildings().empty() && tick < 100000)
+    while (f.bs.getAllBuildings().empty() && tick < 100000)
     {
         runTicks(f.bs, f.belts, 1, tick);
     }
-    REQUIRE(f.bs.allBuildings().size() == 1);
-    REQUIRE(f.bs.allBuildings()[0].type == BuildingType::Splitter);
+    REQUIRE(f.bs.getAllBuildings().size() == 1);
+    REQUIRE(f.bs.getAllBuildings()[0].type == BuildingType::Splitter);
 
     // The built splitter is registered with BeltSystem carrying the filters.
     const std::optional<BeltSystem::SplitterInfo> builtInfo = f.belts.getSplitterInfo(tile);

src/test/CombatSystemTest.cpp

@@ -183,7 +183,7 @@ TEST_CASE("CombatSystem: player station fires at enemy ship in range", "[combat]
     // Find the player station entity via ECS.
     entt::entity stationEntity = entt::null;
     QVector2D stationCenter;
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity e, const StationBodyComponent& sb, const FactionComponent& f)
         {
             if (!f.isEnemy && stationEntity == entt::null)
@@ -194,12 +194,12 @@ TEST_CASE("CombatSystem: player station fires at enemy ship in range", "[combat]
                     sb.anchor.y() + sb.footprint.height() / 2.0f);
             }
         });
-    REQUIRE(sim.admin().isValid(stationEntity));
+    REQUIRE(sim.getAdmin().isValid(stationEntity));
 
-    const ShipDef* combatDef = findCombatShip(sim.config());
+    const ShipDef* combatDef = findCombatShip(sim.getConfig());
     REQUIRE(combatDef != nullptr);
 
-    const entt::entity enemyShip = sim.ships().spawn(
+    const entt::entity enemyShip = sim.getShips().spawn(
         combatDef->id,
         QVector2D(stationCenter.x() + 1.0f, stationCenter.y()),
         /*isEnemy=*/true);
@@ -221,7 +221,7 @@ TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]
 
     entt::entity stationEntity = entt::null;
     QVector2D stationCenter;
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity e, const StationBodyComponent& sb, const FactionComponent& f)
         {
             if (f.isEnemy && stationEntity == entt::null)
@@ -232,12 +232,12 @@ TEST_CASE("CombatSystem: enemy station fires at player ship in range", "[combat]
                     sb.anchor.y() + sb.footprint.height() / 2.0f);
             }
         });
-    REQUIRE(sim.admin().isValid(stationEntity));
+    REQUIRE(sim.getAdmin().isValid(stationEntity));
 
-    const ShipDef* combatDef = findCombatShip(sim.config());
+    const ShipDef* combatDef = findCombatShip(sim.getConfig());
     REQUIRE(combatDef != nullptr);
 
-    sim.ships().spawn(
+    sim.getShips().spawn(
         combatDef->id,
         QVector2D(stationCenter.x() - 1.0f, stationCenter.y()),
         /*isEnemy=*/false);
@@ -259,7 +259,7 @@ TEST_CASE("CombatSystem: player ship fires at enemy station in range", "[combat]
 
     entt::entity stationEntity = entt::null;
     QVector2D stationCenter;
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity e, const StationBodyComponent& sb, const FactionComponent& f)
         {
             if (f.isEnemy && stationEntity == entt::null)
@@ -270,12 +270,12 @@ TEST_CASE("CombatSystem: player ship fires at enemy station in range", "[combat]
                     sb.anchor.y() + sb.footprint.height() / 2.0f);
             }
         });
-    REQUIRE(sim.admin().isValid(stationEntity));
+    REQUIRE(sim.getAdmin().isValid(stationEntity));
 
-    const ShipDef* combatDef = findCombatShip(sim.config());
+    const ShipDef* combatDef = findCombatShip(sim.getConfig());
     REQUIRE(combatDef != nullptr);
 
-    const entt::entity playerShip = sim.ships().spawn(
+    const entt::entity playerShip = sim.getShips().spawn(
         combatDef->id,
         QVector2D(stationCenter.x() - 1.0f, stationCenter.y()),
         /*isEnemy=*/false);
@@ -390,17 +390,17 @@ TEST_CASE("CombatSystem: dead ship is removed after tick step 9", "[combat]")
 {
     Simulation sim(loadConfig(), 42);
 
-    const ShipDef* combatDef = findCombatShip(sim.config());
+    const ShipDef* combatDef = findCombatShip(sim.getConfig());
     REQUIRE(combatDef != nullptr);
 
-    const entt::entity ship = sim.ships().spawn(combatDef->id,
+    const entt::entity ship = sim.getShips().spawn(combatDef->id,
         QVector2D(10.0f, 10.0f));
 
-    sim.admin().get<HealthComponent>(ship).hp = -1.0f;
+    sim.getAdmin().get<HealthComponent>(ship).hp = -1.0f;
 
     sim.tick();
 
-    REQUIRE_FALSE(sim.admin().isValid(ship));
+    REQUIRE_FALSE(sim.getAdmin().isValid(ship));
 }
 
 TEST_CASE("CombatSystem: scrap is spawned on ship death", "[combat]")
@@ -411,15 +411,15 @@ TEST_CASE("CombatSystem: scrap is spawned on ship death", "[combat]")
     // (REQ-RES-SCRAP-DROP): round(threat * scrap_per_threat). The interceptor's
     // threat is 59.0 and the test config sets scrap_per_threat = 1.0, so it drops
     // round(59.0 * 1.0) = 59 scrap.
-    const entt::entity ship = sim.ships().spawn("interceptor",
+    const entt::entity ship = sim.getShips().spawn("interceptor",
         QVector2D(10.0f, 10.0f));
-    sim.admin().get<HealthComponent>(ship).hp = -1.0f;
+    sim.getAdmin().get<HealthComponent>(ship).hp = -1.0f;
 
     sim.tick();
 
-    const std::vector<ScrapInfo> scraps = sim.scraps().allScrapInfo();
+    const std::vector<ScrapInfo> scraps = sim.getScraps().getAllScrapInfo();
     REQUIRE(scraps.size() == 1);
-    CHECK(sim.admin().get<ScrapDataComponent>(scraps[0].entity).amount == 59);
+    CHECK(sim.getAdmin().get<ScrapDataComponent>(scraps[0].entity).amount == 59);
 }
 
 TEST_CASE("CombatSystem: HQ death sets game over", "[combat]")
@@ -427,7 +427,7 @@ TEST_CASE("CombatSystem: HQ death sets game over", "[combat]")
     Simulation sim(loadConfig(), 42);
 
     // Damage the HQ proxy entity (has HqProxy + Health).
-    sim.admin().forEach<HqProxyComponent, HealthComponent>(
+    sim.getAdmin().forEach<HqProxyComponent, HealthComponent>(
         [](entt::entity /*e*/, const HqProxyComponent& /*hq*/, HealthComponent& h)
         {
             h.hp = -1.0f;

src/test/ConfigLoaderTest.cpp

@@ -83,6 +83,16 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     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.");
+
+    // Optional header artifact tooltip (REQ-UI-ARTIFACTS-TOOLTIP).
+    REQUIRE(cfg.world.artifactTooltip.has_value());
+    REQUIRE(*cfg.world.artifactTooltip ==
+            "Choose the artifact reward when destroying enemy stations; collect enough to win.");
+
     // 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));
@@ -113,6 +123,12 @@ TEST_CASE("ConfigLoader loads the committed bin/config/ configs end-to-end", "[c
     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(
         cfg.recipes.recipes.begin(), cfg.recipes.recipes.end(),
@@ -144,6 +160,21 @@ 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

src/test/DeterminismTest.cpp

@@ -67,7 +67,7 @@ TEST_CASE("Hasher: identical inputs produce identical values", "[determinism]")
     b.append(3.5f);
     b.append(std::string("ore"));
 
-    REQUIRE(a.value() == b.value());
+    REQUIRE(a.getValue() == b.getValue());
 }
 
 TEST_CASE("Hasher: differing inputs produce differing values", "[determinism]")
@@ -77,7 +77,7 @@ TEST_CASE("Hasher: differing inputs produce differing values", "[determinism]")
     a.append(42);
     b.append(43);
 
-    REQUIRE(a.value() != b.value());
+    REQUIRE(a.getValue() != b.getValue());
 }
 
 TEST_CASE("Hasher: string concatenation does not collide", "[determinism]")
@@ -89,7 +89,7 @@ TEST_CASE("Hasher: string concatenation does not collide", "[determinism]")
     b.append(std::string("a"));
     b.append(std::string("bc"));
 
-    REQUIRE(a.value() != b.value());
+    REQUIRE(a.getValue() != b.getValue());
 }
 
 TEST_CASE("Hasher: negative and positive zero hash equally", "[determinism]")
@@ -99,7 +99,7 @@ TEST_CASE("Hasher: negative and positive zero hash equally", "[determinism]")
     a.append(-0.0f);
     b.append(0.0f);
 
-    REQUIRE(a.value() == b.value());
+    REQUIRE(a.getValue() == b.getValue());
 }
 
 // ---------------------------------------------------------------------------
@@ -124,7 +124,7 @@ TEST_CASE("Simulation::rngFingerprint is stable for equal seeds", "[determinism]
     const Simulation a(loadConfig(), 777);
     const Simulation b(loadConfig(), 777);
 
-    REQUIRE(a.rngFingerprint() == b.rngFingerprint());
+    REQUIRE(a.getRngFingerprint() == b.getRngFingerprint());
 }
 
 // ---------------------------------------------------------------------------

src/test/FormulaTest.cpp

@@ -37,7 +37,7 @@ TEST_CASE("Formula retains its source string", "[formula]")
     const std::string source = "10 + x / 5";
     const Formula f = Formula::compile(source);
 
-    REQUIRE(f.source() == source);
+    REQUIRE(f.getSource() == source);
 }
 
 TEST_CASE("Formula throws on malformed source", "[formula]")

src/test/RecipeSchematicTest.cpp

@@ -22,7 +22,7 @@ static GameConfig loadConfig()
 // tickDeathsAndLoot fires, triggering the push and schematic choices.
 static void killEnemyStations(Simulation& sim)
 {
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity, StationBodyComponent&, FactionComponent& faction, HealthComponent& health)
         {
             if (faction.isEnemy)

src/test/ReplayPlaybackTest.cpp

@@ -166,7 +166,7 @@ TEST_CASE("a recorded run replays to byte-identical state with no desync", "[rep
         manager.drain();
         for (int i = 0; i < 60; ++i) { rec.tick(); manager.recordTickCheckpoint(); }
 
-        replayPath = recorderPtr->currentFilePath();
+        replayPath = recorderPtr->getCurrentFilePath();
         recordedFinalChecksum = rec.computeStateChecksum();
         manager.setRecorder(nullptr);  // close the file
     }
@@ -185,11 +185,11 @@ TEST_CASE("a recorded run replays to byte-identical state with no desync", "[rep
     while (!player.isFinished())
     {
         play.tick();
-        player.advanceTo(play.currentTick());
+        player.advanceTo(play.getCurrentTick());
     }
 
     REQUIRE_FALSE(player.getDesyncTick().has_value());
-    REQUIRE(play.currentTick() == 150);
+    REQUIRE(play.getCurrentTick() == 150);
     REQUIRE(play.computeStateChecksum() == recordedFinalChecksum);
 
     QFile::remove(QString::fromStdString(replayPath));
@@ -208,7 +208,7 @@ TEST_CASE("ReplayPlayer reports a desync when a checksum is corrupted", "[replay
         ReplayRecorder* recorderPtr = recorder.get();
         manager.setRecorder(std::move(recorder));
         for (int i = 0; i < 60; ++i) { rec.tick(); manager.recordTickCheckpoint(); }
-        replayPath = recorderPtr->currentFilePath();
+        replayPath = recorderPtr->getCurrentFilePath();
         manager.setRecorder(nullptr);
     }
 
@@ -234,7 +234,7 @@ TEST_CASE("ReplayPlayer reports a desync when a checksum is corrupted", "[replay
     while (!player.isFinished())
     {
         play.tick();
-        player.advanceTo(play.currentTick());
+        player.advanceTo(play.getCurrentTick());
     }
 
     REQUIRE(player.getDesyncTick().has_value());
@@ -267,7 +267,7 @@ TEST_CASE("a long recorded run (through waves and combat) replays with no desync
         manager.drain();
         for (int i = 0; i < 900; ++i) { rec.tick(); manager.recordTickCheckpoint(); }
 
-        replayPath = recorderPtr->currentFilePath();
+        replayPath = recorderPtr->getCurrentFilePath();
         recordedFinalChecksum = rec.computeStateChecksum();
         manager.setRecorder(nullptr);
     }
@@ -281,11 +281,11 @@ TEST_CASE("a long recorded run (through waves and combat) replays with no desync
     while (!player.isFinished())
     {
         play.tick();
-        player.advanceTo(play.currentTick());
+        player.advanceTo(play.getCurrentTick());
     }
 
     REQUIRE_FALSE(player.getDesyncTick().has_value());
-    REQUIRE(play.currentTick() == 2400);
+    REQUIRE(play.getCurrentTick() == 2400);
     REQUIRE(play.computeStateChecksum() == recordedFinalChecksum);
 
     QFile::remove(QString::fromStdString(replayPath));

src/test/ReplayRecorderTest.cpp

@@ -120,7 +120,7 @@ TEST_CASE("ReplayRecorder writes a well-formed file", "[replay]")
 
     recorder.recordChecksum(30, 0x0ffffffffffffff0ull);
 
-    const std::string path = recorder.currentFilePath();
+    const std::string path = recorder.getCurrentFilePath();
     REQUIRE_FALSE(path.empty());
     recorder.close();
 
@@ -152,7 +152,7 @@ TEST_CASE("CommandManager records commands and an initial checksum on drain", "[
     ReplayRecorder* recorderPtr = recorder.get();
     // setRecorder opens the file and writes the header + the tick-0 checksum.
     manager.setRecorder(std::move(recorder));
-    const std::string path = recorderPtr->currentFilePath();
+    const std::string path = recorderPtr->getCurrentFilePath();
     REQUIRE_FALSE(path.empty());
 
     std::shared_ptr<PlaceBuildingCommand> place = std::make_shared<PlaceBuildingCommand>();
@@ -175,10 +175,10 @@ TEST_CASE("ReplayRecorder startNewRun rolls to a new file", "[replay]")
     ReplayRecorder recorder(CONFIG_DIR, tempOutputDir());
 
     recorder.startNewRun(1u, 0ull);
-    const std::string first = recorder.currentFilePath();
+    const std::string first = recorder.getCurrentFilePath();
 
     recorder.startNewRun(2u, 0ull);
-    const std::string second = recorder.currentFilePath();
+    const std::string second = recorder.getCurrentFilePath();
 
     REQUIRE(first != second);
     REQUIRE(second.find("_2.replay") != std::string::npos);
@@ -194,7 +194,7 @@ TEST_CASE("CommandManager rolls the replay file on a Reset command", "[replay]")
         std::make_unique<ReplayRecorder>(CONFIG_DIR, tempOutputDir());
     ReplayRecorder* recorderPtr = recorder.get();
     manager.setRecorder(std::move(recorder));
-    const std::string firstPath = recorderPtr->currentFilePath();
+    const std::string firstPath = recorderPtr->getCurrentFilePath();
 
     std::shared_ptr<ResetCommand> reset = std::make_shared<ResetCommand>();
     reset->config = std::make_shared<GameConfig>(ConfigLoader::loadFromDirectory(CONFIG_DIR));
@@ -202,7 +202,7 @@ TEST_CASE("CommandManager rolls the replay file on a Reset command", "[replay]")
     manager.enqueue(reset);
     manager.drain();
 
-    const std::string secondPath = recorderPtr->currentFilePath();
+    const std::string secondPath = recorderPtr->getCurrentFilePath();
     REQUIRE(firstPath != secondPath);
     REQUIRE(secondPath.find("_999.replay") != std::string::npos);
 

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
 // ---------------------------------------------------------------------------
@@ -137,6 +148,81 @@ TEST_CASE("ScrapSystem: allScrapInfo returns all spawned scrap", "[scrap]")
     ss.spawn(QVector2D(1.0f, 2.0f), 3, 100);
     ss.spawn(QVector2D(4.0f, 5.0f), 6, 200);
 
-    const std::vector<ScrapInfo> info = ss.allScrapInfo();
+    const std::vector<ScrapInfo> info = ss.getAllScrapInfo();
     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.getAllScrapInfo();
+    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

@@ -87,7 +87,7 @@ static void fillMaterials(Simulation& sim, BuildingId yardId,
         }
         for (const PlacedModule& pm : layout.placedModules)
         {
-            for (const ModuleDef& modDef : sim.config().modules.modules)
+            for (const ModuleDef& modDef : sim.getConfig().modules.modules)
             {
                 if (modDef.id == pm.moduleId)
                 {
@@ -109,22 +109,22 @@ static void fillMaterials(Simulation& sim, BuildingId yardId,
 TEST_CASE("Ship spawn: no modules leaves base stats unchanged", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
     const float expectedHp = static_cast<float>(def->health.hp);
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, std::nullopt);
 
-    REQUIRE(sim.admin().isValid(e));
-    CHECK(sim.admin().get<HealthComponent>(e).maxHp == Approx(expectedHp));
+    REQUIRE(sim.getAdmin().isValid(e));
+    CHECK(sim.getAdmin().get<HealthComponent>(e).maxHp == Approx(expectedHp));
 }
 
 TEST_CASE("Ship spawn: multiplicative HP module applies correctly", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
     const float baseHp = static_cast<float>(def->health.hp);
@@ -136,23 +136,23 @@ TEST_CASE("Ship spawn: multiplicative HP module applies correctly", "[modules]")
     pm.rotation = Rotation::East;
     layout.placedModules.push_back(pm);
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
-    REQUIRE(sim.admin().isValid(e));
+    REQUIRE(sim.getAdmin().isValid(e));
     // armor_plate has multiplied_hp_formula = "1.5"
     // final = base * (1 + (1.5 - 1)) + 0 = base * 1.5
-    CHECK(sim.admin().get<HealthComponent>(e).maxHp == Approx(baseHp * 1.5f));
-    CHECK(sim.admin().get<HealthComponent>(e).hp == sim.admin().get<HealthComponent>(e).maxHp);
+    CHECK(sim.getAdmin().get<HealthComponent>(e).maxHp == Approx(baseHp * 1.5f));
+    CHECK(sim.getAdmin().get<HealthComponent>(e).hp == sim.getAdmin().get<HealthComponent>(e).maxHp);
 }
 
 TEST_CASE("Ship spawn: additive sensor module applies correctly", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
-    const float tileSize = static_cast<float>(sim.config().world.tileSize_m);
+    const float tileSize = static_cast<float>(sim.getConfig().world.tileSize_m);
     const float baseRange_tiles = static_cast<float>(def->sensor.sensorRange_m) / tileSize;
 
     ShipLayoutConfig layout;
@@ -162,19 +162,19 @@ TEST_CASE("Ship spawn: additive sensor module applies correctly", "[modules]")
     pm.rotation = Rotation::East;
     layout.placedModules.push_back(pm);
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
-    REQUIRE(sim.admin().isValid(e));
+    REQUIRE(sim.getAdmin().isValid(e));
     // sensor_booster has added_sensor_range_m_formula = "100" m → 100/10 = 10 tiles
     // final = baseRange_tiles * 1.0 + 10 = baseRange_tiles + 10
-    CHECK(sim.admin().get<SensorRangeComponent>(e).value_tiles == Approx(baseRange_tiles + 10.0f));
+    CHECK(sim.getAdmin().get<SensorRangeComponent>(e).value_tiles == Approx(baseRange_tiles + 10.0f));
 }
 
 TEST_CASE("Ship spawn: multiple modules stack correctly", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
     const float baseHp = static_cast<float>(def->health.hp);
@@ -189,14 +189,14 @@ TEST_CASE("Ship spawn: multiple modules stack correctly", "[modules]")
         layout.placedModules.push_back(pm);
     }
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
-    REQUIRE(sim.admin().isValid(e));
+    REQUIRE(sim.getAdmin().isValid(e));
     // Two armor_plates: each 1.5 multiplier
     // total_mult = 1 + (1.5 - 1) + (1.5 - 1) = 2.0
     // final = base * 2.0
-    CHECK(sim.admin().get<HealthComponent>(e).maxHp == Approx(baseHp * 2.0f));
+    CHECK(sim.getAdmin().get<HealthComponent>(e).maxHp == Approx(baseHp * 2.0f));
 }
 
 // ---------------------------------------------------------------------------
@@ -207,7 +207,7 @@ TEST_CASE("Shipyard: setShipLayout reinitializes buffers with module materials",
           "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -222,7 +222,7 @@ TEST_CASE("Shipyard: setShipLayout reinitializes buffers with module materials",
 
     SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
 
-    const Building* b = sim.buildings().findBuilding(yardId);
+    const Building* b = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b != nullptr);
     // armor_plate needs 2 iron_ingot; interceptor needs 3 iron_ingot + 1 circuit_board
     // Total iron_ingot = 5, buffer cap = 2 * 5 = 10
@@ -234,9 +234,9 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
           "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -247,7 +247,7 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
     fillMaterials(sim, yardId, *def, emptyLayout);
     sim.tick();
 
-    const Building* b1 = sim.buildings().findBuilding(yardId);
+    const Building* b1 = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b1 != nullptr);
     REQUIRE(b1->production.has_value());
 
@@ -261,7 +261,7 @@ TEST_CASE("Shipyard: setShipLayout cancels in-progress production",
 
     SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
 
-    const Building* b2 = sim.buildings().findBuilding(yardId);
+    const Building* b2 = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b2 != nullptr);
     CHECK_FALSE(b2->production.has_value());
 }
@@ -270,7 +270,7 @@ 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");
+    const ShipDef* def = findSchematic(sim.getConfig(), "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
@@ -278,7 +278,7 @@ TEST_CASE("Shipyard: builds a bare hull when no layout is configured",
     // base-hull materials it was charged.
     REQUIRE_FALSE(def->defaultModules.empty());
 
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -297,23 +297,23 @@ TEST_CASE("Shipyard: builds a bare hull when no layout is configured",
 
     // Locate the freshly built player ship.
     entt::entity built = entt::null;
-    sim.admin().forEach<ShipIdentityComponent, FactionComponent>(
+    sim.getAdmin().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));
+    REQUIRE(sim.getAdmin().isValid(built));
 
     // Bare hull: the schematic's default weapon must NOT have been installed.
     const bool hasWeapon =
-        findFirstWeaponChild(sim.admin(), built) != entt::null;
+        findFirstWeaponChild(sim.getAdmin(), built) != entt::null;
     CHECK_FALSE(hasWeapon);
 }
 
 TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -327,13 +327,13 @@ TEST_CASE("Shipyard: setRecipe clears ship layout", "[modules][shipyard]")
     layout.placedModules.push_back(pm);
     SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
 
-    const Building* b1 = sim.buildings().findBuilding(yardId);
+    const Building* b1 = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b1 != nullptr);
     REQUIRE(b1->shipLayout.has_value());
 
     SimulationTestAccess::buildings(sim).setRecipe(yardId,"destroyer");
 
-    const Building* b2 = sim.buildings().findBuilding(yardId);
+    const Building* b2 = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b2 != nullptr);
     CHECK_FALSE(b2->shipLayout.has_value());
 }
@@ -342,7 +342,7 @@ TEST_CASE("Shipyard: setRecipe with unchanged recipe keeps ship layout",
           "[modules][shipyard]")
 {
     Simulation sim(loadConfig(), 42);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -356,14 +356,14 @@ TEST_CASE("Shipyard: setRecipe with unchanged recipe keeps ship layout",
     layout.placedModules.push_back(pm);
     SimulationTestAccess::buildings(sim).setShipLayout(yardId, layout);
 
-    const Building* b1 = sim.buildings().findBuilding(yardId);
+    const Building* b1 = sim.getBuildings().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);
+    const Building* b2 = sim.getBuildings().findBuilding(yardId);
     REQUIRE(b2 != nullptr);
     REQUIRE(b2->shipLayout.has_value());
     REQUIRE(b2->shipLayout->placedModules.size() == 1);
@@ -377,7 +377,7 @@ TEST_CASE("Shipyard: setRecipe with unchanged recipe keeps ship layout",
 TEST_CASE("Ship spawn: weapon_primer multiplies attack rate in simulation", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
     ShipLayoutConfig layout;
@@ -390,22 +390,22 @@ TEST_CASE("Ship spawn: weapon_primer multiplies attack rate in simulation", "[mo
         layout.placedModules.push_back(pm);
     }
 
-    const entt::entity ship = sim.ships().spawn("interceptor",
+    const entt::entity ship = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
-    const entt::entity weapon = findFirstWeaponChild(sim.admin(), ship);
-    REQUIRE(sim.admin().isValid(weapon));
+    const entt::entity weapon = findFirstWeaponChild(sim.getAdmin(), ship);
+    REQUIRE(sim.getAdmin().isValid(weapon));
     // base rate = 2.0 hz; weapon_primer multiplier = 1.2 → 2.4 hz
-    CHECK(sim.admin().get<WeaponComponent>(weapon).fireRateHz == Approx(2.4f));
+    CHECK(sim.getAdmin().get<WeaponComponent>(weapon).fireRateHz == Approx(2.4f));
 }
 
 TEST_CASE("Ship spawn: weapon_stabilizer multiplies attack range in simulation", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
-    const float tileSize = static_cast<float>(sim.config().world.tileSize_m);
+    const float tileSize = static_cast<float>(sim.getConfig().world.tileSize_m);
 
     ShipLayoutConfig layout;
     for (const std::string& id : {"laser_cannon", "weapon_stabilizer"})
@@ -417,22 +417,22 @@ TEST_CASE("Ship spawn: weapon_stabilizer multiplies attack range in simulation",
         layout.placedModules.push_back(pm);
     }
 
-    const entt::entity ship = sim.ships().spawn("interceptor",
+    const entt::entity ship = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
-    const entt::entity weapon = findFirstWeaponChild(sim.admin(), ship);
-    REQUIRE(sim.admin().isValid(weapon));
+    const entt::entity weapon = findFirstWeaponChild(sim.getAdmin(), ship);
+    REQUIRE(sim.getAdmin().isValid(weapon));
     // base range = 50 m / tileSize = 5 tiles; weapon_stabilizer multiplier = 1.5 → 7.5 tiles
-    CHECK(sim.admin().get<WeaponComponent>(weapon).range_tiles == Approx(50.0f / tileSize * 1.5f));
+    CHECK(sim.getAdmin().get<WeaponComponent>(weapon).range_tiles == Approx(50.0f / tileSize * 1.5f));
 }
 
 TEST_CASE("Ship spawn: afterburner additive main_acceleration is converted m/s² to tiles/tick", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
-    const float tileSize   = static_cast<float>(sim.config().world.tileSize_m);
+    const float tileSize   = static_cast<float>(sim.getConfig().world.tileSize_m);
     const float tickRate   = static_cast<float>(kTickRateHz);
     const float base_mpss  = static_cast<float>(def->movement.mainAcceleration_mpss);
 
@@ -443,21 +443,21 @@ TEST_CASE("Ship spawn: afterburner additive main_acceleration is converted m/s²
     pm.rotation = Rotation::East;
     layout.placedModules.push_back(pm);
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
     // added_main_acceleration_mpss = 60; same conversion as base: / tileSize / tickRate
     const float expected = (base_mpss + 60.0f) / tileSize / tickRate;
-    CHECK(sim.admin().get<DynamicBodyComponent>(e).mainAcceleration_tptt == Approx(expected));
+    CHECK(sim.getAdmin().get<DynamicBodyComponent>(e).mainAcceleration_tptt == Approx(expected));
 }
 
 TEST_CASE("Ship spawn: maneuvering_thrusters additive maneuvering_acceleration is converted m/s² to tiles/tick", "[modules]")
 {
     Simulation sim(loadConfig(), 42);
-    const ShipDef* def = findSchematic(sim.config(), "interceptor");
+    const ShipDef* def = findSchematic(sim.getConfig(), "interceptor");
     REQUIRE(def != nullptr);
 
-    const float tileSize   = static_cast<float>(sim.config().world.tileSize_m);
+    const float tileSize   = static_cast<float>(sim.getConfig().world.tileSize_m);
     const float tickRate   = static_cast<float>(kTickRateHz);
     const float base_mpss  = static_cast<float>(def->movement.maneuveringAcceleration_mpss);
 
@@ -468,12 +468,12 @@ TEST_CASE("Ship spawn: maneuvering_thrusters additive maneuvering_acceleration i
     pm.rotation = Rotation::East;
     layout.placedModules.push_back(pm);
 
-    const entt::entity e = sim.ships().spawn("interceptor",
+    const entt::entity e = sim.getShips().spawn("interceptor",
         QVector2D(5.0f, 5.0f), false, layout);
 
     // added_maneuvering_acceleration_mpss = 10; same conversion as base: / tileSize / tickRate
     const float expected = (base_mpss + 10.0f) / tileSize / tickRate;
-    CHECK(sim.admin().get<DynamicBodyComponent>(e).maneuveringAcceleration_tptt == Approx(expected));
+    CHECK(sim.getAdmin().get<DynamicBodyComponent>(e).maneuveringAcceleration_tptt == Approx(expected));
 }
 
 // ---------------------------------------------------------------------------

src/test/ShipyardTest.cpp

@@ -56,7 +56,7 @@ static BuildingId placeShipyard(Simulation& sim, const BuildingDef& yardDef)
 static int countShips(Simulation& sim)
 {
     int n = 0;
-    sim.admin().forEach<ShipIdentityComponent>(
+    sim.getAdmin().forEach<ShipIdentityComponent>(
         [&n](entt::entity /*e*/, const ShipIdentityComponent& /*si*/) { ++n; });
     return n;
 }
@@ -85,9 +85,9 @@ TEST_CASE("Shipyard: spawns a player ship after production cycle completes",
 {
     Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableSchematic(sim.config());
+    const ShipDef* def = findAvailableSchematic(sim.getConfig());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = countShips(sim);
@@ -115,7 +115,7 @@ TEST_CASE("Shipyard: spawns a player ship after production cycle completes",
     REQUIRE(countShips(sim) == shipsBefore + 1);
 
     bool foundPlayerShip = false;
-    sim.admin().forEach<ShipIdentityComponent, FactionComponent>(
+    sim.getAdmin().forEach<ShipIdentityComponent, FactionComponent>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& si, const FactionComponent& f)
         {
             if (!f.isEnemy && si.schematicId == def->id)
@@ -130,7 +130,7 @@ TEST_CASE("Shipyard: does not spawn without a schematic set", "[shipyard]")
 {
     Simulation sim(loadConfig(), 42);
 
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = countShips(sim);
@@ -146,9 +146,9 @@ TEST_CASE("Shipyard: does not spawn with insufficient materials", "[shipyard]")
 {
     Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableSchematic(sim.config());
+    const ShipDef* def = findAvailableSchematic(sim.getConfig());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const int shipsBefore = countShips(sim);
@@ -170,9 +170,9 @@ TEST_CASE("Shipyard: spawns a second ship after materials replenished", "[shipya
 {
     Simulation sim(loadConfig(), 42);
 
-    const ShipDef* def = findAvailableSchematic(sim.config());
+    const ShipDef* def = findAvailableSchematic(sim.getConfig());
     REQUIRE(def != nullptr);
-    const BuildingDef* yardDef = findShipyardDef(sim.config());
+    const BuildingDef* yardDef = findShipyardDef(sim.getConfig());
     REQUIRE(yardDef != nullptr);
 
     const BuildingId yardId = placeShipyard(sim, *yardDef);
@@ -203,7 +203,7 @@ TEST_CASE("Shipyard: spawns a second ship after materials replenished", "[shipya
     // Verify the shipyard production field cleared (i.e. the cycle completed
     // and is not still running).
     bool productionCleared = false;
-    for (const Building& b : sim.buildings().allBuildings())
+    for (const Building& b : sim.getBuildings().getAllBuildings())
     {
         if (b.id == yardId)
         {

src/test/SimulationTest.cpp

@@ -19,7 +19,7 @@ TEST_CASE("Simulation::currentTick starts at 0", "[simulation]")
 {
     const Simulation sim(loadConfig());
 
-    REQUIRE(sim.currentTick() == 0);
+    REQUIRE(sim.getCurrentTick() == 0);
 }
 
 TEST_CASE("Simulation::tick increments currentTick by 1", "[simulation]")
@@ -28,7 +28,7 @@ TEST_CASE("Simulation::tick increments currentTick by 1", "[simulation]")
 
     sim.tick();
 
-    REQUIRE(sim.currentTick() == 1);
+    REQUIRE(sim.getCurrentTick() == 1);
 }
 
 TEST_CASE("Simulation::tick 10 times yields currentTick == 10", "[simulation]")
@@ -40,7 +40,7 @@ TEST_CASE("Simulation::tick 10 times yields currentTick == 10", "[simulation]")
         sim.tick();
     }
 
-    REQUIRE(sim.currentTick() == 10);
+    REQUIRE(sim.getCurrentTick() == 10);
 }
 
 TEST_CASE("Simulation::drainBeamFiredEvents returns empty initially", "[simulation]")
@@ -131,3 +131,26 @@ TEST_CASE("TickDriver::reset clears the accumulator", "[simulation]")
     // Nothing in the accumulator: zero elapsed time should not fire.
     REQUIRE(driver.advance(0.0, 1.0) == 0);
 }
+
+TEST_CASE("TickDriver::reset discards a large pending delta so a restart does not "
+          "fast-forward", "[simulation]")
+{
+    // Regression guard for the "restart fast-forwards by the time spent in the
+    // Game Over / Win / escape dialog" bug: on restart the frame timer holds the
+    // whole wall-clock duration the modal was open. GameWorldView::resetForNewGame()
+    // now calls TickDriver::reset() to discard that pending delta; without it the
+    // fresh run would burst forward by the dialog duration on its first frame.
+    TickDriver driver;
+
+    // 30 seconds spent in the dialog would otherwise be ~900 ticks at 30 Hz.
+    const double dialogOpenMs = 30000.0;
+    driver.reset();
+
+    // A brand-new run's first normal frame (~16 ms) advances only its own ticks;
+    // the discarded dialog time contributes nothing.
+    REQUIRE(driver.advance(16.0, 1.0) == 0);
+
+    // Sanity: had the dialog delta not been discarded, it would have fired ~900 ticks.
+    TickDriver leaked;
+    REQUIRE(leaked.advance(dialogOpenMs, 1.0) > 800);
+}

src/test/SimulationTestAccess.h

@@ -22,8 +22,8 @@ class BuildingSystem;
 // reached via buildings(sim)/belts(sim).
 struct SimulationTestAccess
 {
-    static BuildingSystem& buildings(Simulation& sim) { return sim.buildingsMutable(); }
-    static BeltSystem&     belts(Simulation& sim)     { return sim.beltsMutable(); }
+    static BuildingSystem& buildings(Simulation& sim) { return sim.getBuildingsMutable(); }
+    static BeltSystem&     belts(Simulation& sim)     { return sim.getBeltsMutable(); }
 
     static BuildingId place(Simulation& sim, BuildingType type, QPoint anchor,
                             Rotation rotation)

src/test/UnlockPrereqTest.cpp

@@ -67,7 +67,7 @@ RecipeDef& findRecipe(GameConfig& cfg, const std::string& id)
 // tickDeathsAndLoot fires, triggering the push and schematic choices.
 void killEnemyStations(Simulation& sim)
 {
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity, StationBodyComponent&, FactionComponent& faction, HealthComponent& health)
         {
             if (faction.isEnemy)

src/test/WaveSystemTest.cpp

@@ -49,7 +49,7 @@ TEST_CASE("WaveSystem: threat accumulates at boss wave counter rate", "[wave]")
         ws.tickThreatAccumulation();
     }
 
-    REQUIRE(ws.threatLevel() == Approx(1.0));
+    REQUIRE(ws.getThreatLevel() == Approx(1.0));
 }
 
 TEST_CASE("WaveSystem: threatAccumulationRate matches the rate formula outside quiet windows",
@@ -60,7 +60,7 @@ TEST_CASE("WaveSystem: threatAccumulationRate matches the rate formula outside q
     WaveSystem ws(cfg, rng);
 
     // threat_rate_formula = "x", boss wave counter starts at 1 → rate = 1 threat/s.
-    REQUIRE(ws.threatAccumulationRate() == Approx(1.0));
+    REQUIRE(ws.getThreatAccumulationRate() == Approx(1.0));
 }
 
 TEST_CASE("WaveSystem: threatAccumulationRate is 0 during a quiet window", "[wave]")
@@ -71,14 +71,14 @@ TEST_CASE("WaveSystem: threatAccumulationRate is 0 during a quiet window", "[wav
     std::mt19937 rng(42);
     WaveSystem ws(cfg, rng);
 
-    REQUIRE(ws.threatAccumulationRate() == Approx(0.0));
+    REQUIRE(ws.getThreatAccumulationRate() == Approx(0.0));
 
-    const double before = ws.threatLevel();
+    const double before = ws.getThreatLevel();
     for (int i = 0; i < static_cast<int>(secondsToTicks(1.0)); ++i)
     {
         ws.tickThreatAccumulation();
     }
-    REQUIRE(ws.threatLevel() == Approx(before));
+    REQUIRE(ws.getThreatLevel() == Approx(before));
 }
 
 TEST_CASE("WaveSystem: generation starts at 0 and increments on station destruction", "[wave]")
@@ -87,11 +87,11 @@ TEST_CASE("WaveSystem: generation starts at 0 and increments on station destruct
     std::mt19937 rng(42);
     WaveSystem ws(cfg, rng);
 
-    REQUIRE(ws.generation() == 0);
+    REQUIRE(ws.getGeneration() == 0);
     ws.onEnemyStationsDestroyed();
-    REQUIRE(ws.generation() == 1);
+    REQUIRE(ws.getGeneration() == 1);
     ws.onEnemyStationsDestroyed();
-    REQUIRE(ws.generation() == 2);
+    REQUIRE(ws.getGeneration() == 2);
 }
 
 // ---------------------------------------------------------------------------
@@ -104,7 +104,7 @@ TEST_CASE("WaveSystem: Simulation pre-places HQ + 2 player + 2 enemy stations",
 
     // HQ is still a Building (for belt integration).
     int hqCount = 0;
-    for (const Building& b : sim.buildings().allBuildings())
+    for (const Building& b : sim.getBuildings().getAllBuildings())
     {
         if (b.type == BuildingType::Hq) { ++hqCount; }
     }
@@ -112,7 +112,7 @@ TEST_CASE("WaveSystem: Simulation pre-places HQ + 2 player + 2 enemy stations",
     // Stations are ECS entities.
     int playerCount = 0;
     int enemyCount  = 0;
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f)
         {
             if (f.isEnemy) { ++enemyCount; }
@@ -129,10 +129,10 @@ TEST_CASE("WaveSystem: HQ has correct initial HP from config", "[wave]")
     const Simulation sim(loadConfig(), 42);
 
     const float expectedHp =
-        static_cast<float>(sim.config().stations.hq.hpFormula.evaluate(0.0));
+        static_cast<float>(sim.getConfig().stations.hq.hpFormula.evaluate(0.0));
     bool found = false;
     float actualHp = 0.0f;
-    sim.admin().forEach<HqProxyComponent, HealthComponent>(
+    sim.getAdmin().forEach<HqProxyComponent, HealthComponent>(
         [&](entt::entity /*e*/, const HqProxyComponent& /*hq*/, const HealthComponent& h)
         {
             found    = true;
@@ -147,7 +147,7 @@ TEST_CASE("WaveSystem: HQ anchor is at asteroid right edge", "[wave]")
 {
     const Simulation sim(loadConfig(), 42);
 
-    for (const Building& b : sim.buildings().allBuildings())
+    for (const Building& b : sim.getBuildings().getAllBuildings())
     {
         if (b.type != BuildingType::Hq) { continue; }
         // Rightmost body cell must be at x = -1 (asteroid right edge).
@@ -165,11 +165,11 @@ TEST_CASE("WaveSystem: player stations have weapon set", "[wave]")
     Simulation sim(loadConfig(), 42);
 
     int armedPlayerStations = 0;
-    sim.admin().forEach<WeaponComponent, ModuleOwnerComponent>(
+    sim.getAdmin().forEach<WeaponComponent, ModuleOwnerComponent>(
         [&](entt::entity /*e*/, const WeaponComponent& w, const ModuleOwnerComponent& mo)
         {
-            if (!sim.admin().hasAll<StationBodyComponent>(mo.owner)) { return; }
-            const FactionComponent& f = sim.admin().get<FactionComponent>(mo.owner);
+            if (!sim.getAdmin().hasAll<StationBodyComponent>(mo.owner)) { return; }
+            const FactionComponent& f = sim.getAdmin().get<FactionComponent>(mo.owner);
             if (!f.isEnemy)
             {
                 ++armedPlayerStations;
@@ -186,11 +186,11 @@ TEST_CASE("WaveSystem: enemy stations have weapon set", "[wave]")
     Simulation sim(loadConfig(), 42);
 
     int armedEnemyStations = 0;
-    sim.admin().forEach<WeaponComponent, ModuleOwnerComponent>(
+    sim.getAdmin().forEach<WeaponComponent, ModuleOwnerComponent>(
         [&](entt::entity /*e*/, const WeaponComponent& w, const ModuleOwnerComponent& mo)
         {
-            if (!sim.admin().hasAll<StationBodyComponent>(mo.owner)) { return; }
-            const FactionComponent& f = sim.admin().get<FactionComponent>(mo.owner);
+            if (!sim.getAdmin().hasAll<StationBodyComponent>(mo.owner)) { return; }
+            const FactionComponent& f = sim.getAdmin().get<FactionComponent>(mo.owner);
             if (f.isEnemy)
             {
                 ++armedEnemyStations;
@@ -221,7 +221,7 @@ TEST_CASE("WaveSystem: enemy ships spawn after the initial gap elapses", "[wave]
         sim.tick();
         if (!foundEnemyShip)
         {
-            sim.admin().forEach<ShipIdentityComponent, FactionComponent>(
+            sim.getAdmin().forEach<ShipIdentityComponent, FactionComponent>(
                 [&](entt::entity /*e*/, const ShipIdentityComponent& /*si*/,
                     const FactionComponent& f)
                 {
@@ -253,7 +253,7 @@ TEST_CASE("WaveSystem: destroying both enemy stations triggers a push", "[wave]"
     Simulation sim(loadConfig(), 42);
 
     // Damage both enemy stations to 0.
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -263,7 +263,7 @@ TEST_CASE("WaveSystem: destroying both enemy stations triggers a push", "[wave]"
 
     // After push: should have 2 new enemy stations.
     int enemyCount = 0;
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f)
         {
             if (f.isEnemy) { ++enemyCount; }
@@ -275,7 +275,7 @@ TEST_CASE("WaveSystem: push generates pending schematic choices", "[wave]")
 {
     Simulation sim(loadConfig(), 42);
 
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -293,7 +293,7 @@ TEST_CASE("WaveSystem: push schematic choices have valid ids", "[wave]")
 {
     Simulation sim(loadConfig(), 42);
 
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -306,20 +306,20 @@ TEST_CASE("WaveSystem: push schematic choices have valid ids", "[wave]")
     for (const SchematicChoiceOption& opt : choices)
     {
         bool validId = false;
-        for (const ShipDef& def : sim.config().ships.ships)
+        for (const ShipDef& def : sim.getConfig().ships.ships)
         {
             if (def.id == opt.schematicId) { validId = true; break; }
         }
         if (!validId)
         {
-            for (const ModuleDef& def : sim.config().modules.modules)
+            for (const ModuleDef& def : sim.getConfig().modules.modules)
             {
                 if (def.id == opt.schematicId) { validId = true; break; }
             }
         }
         if (!validId)
         {
-            for (const RecipeDef& def : sim.config().recipes.recipes)
+            for (const RecipeDef& def : sim.getConfig().recipes.recipes)
             {
                 if (def.id == opt.schematicId) { validId = true; break; }
             }
@@ -332,7 +332,7 @@ TEST_CASE("WaveSystem: schematic choices have no duplicates", "[wave]")
 {
     Simulation sim(loadConfig(), 42);
 
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -352,7 +352,7 @@ TEST_CASE("WaveSystem: applySchematicChoice clears pending and applies", "[wave]
 {
     Simulation sim(loadConfig(), 42);
 
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -370,7 +370,7 @@ TEST_CASE("WaveSystem: push places new enemy stations further right", "[wave]")
 
     // Record the X position of the initial enemy stations.
     int initialX = std::numeric_limits<int>::min();
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity /*e*/, const StationBodyComponent& sb, const FactionComponent& f)
         {
             if (f.isEnemy && sb.anchor.x() > initialX)
@@ -379,7 +379,7 @@ TEST_CASE("WaveSystem: push places new enemy stations further right", "[wave]")
             }
         });
 
-    sim.admin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent, HealthComponent>(
         [](entt::entity /*e*/, const StationBodyComponent& /*sb*/, const FactionComponent& f, HealthComponent& h)
         {
             if (f.isEnemy) { h.hp = -1.0f; }
@@ -387,7 +387,7 @@ TEST_CASE("WaveSystem: push places new enemy stations further right", "[wave]")
     sim.tick();
 
     int newX = std::numeric_limits<int>::min();
-    sim.admin().forEach<StationBodyComponent, FactionComponent>(
+    sim.getAdmin().forEach<StationBodyComponent, FactionComponent>(
         [&](entt::entity /*e*/, const StationBodyComponent& sb, const FactionComponent& f)
         {
             if (f.isEnemy && sb.anchor.x() > newX)

src/ui/BlueprintPanel.cpp

@@ -146,66 +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;
-        // Recipe / schematic / layout / splitter-filter capture is shared with the
-        // copy-settings gesture (REQ-BLD-COPY-CONFIG) via readBuildingConfig.
-        const std::optional<BuildingConfig> config =
-            readBuildingConfig(*m_sim, e.building->id);
-        if (config.has_value())
-        {
-            bb.recipeId        = config->recipeId.value_or(std::string());
-            bb.shipLayout      = config->shipLayout;
-            bb.splitterFilterA = config->splitterFilterA;
-            bb.splitterFilterB = config->splitterFilterB;
-        }
-        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
@@ -213,14 +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;
 }
@@ -239,7 +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);
@@ -307,19 +245,8 @@ void BlueprintPanel::loadFromDisk()
 
 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)
     {

src/ui/BuildButtonGrid.cpp

@@ -12,12 +12,13 @@
 #include "DisplayName.h"
 #include "EventManager.h"
 #include "ExitBuilderModeRequestedEvent.h"
+#include "Simulation.h"
 
 
-BuildButtonGrid::BuildButtonGrid(const GameConfig* config, QWidget* parent)
+BuildButtonGrid::BuildButtonGrid(Simulation* sim, const GameConfig* config, QWidget* parent)
     : QWidget(parent)
+    , m_sim(sim)
     , m_config(config)
-    , m_activeIndex(-1)
 {
     QGridLayout* layout = new QGridLayout(this);
     layout->setSpacing(4);
@@ -38,10 +39,14 @@ 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());
@@ -75,24 +80,42 @@ BuildButtonGrid::~BuildButtonGrid()
     unregisterForEvents();
 }
 
-void BuildButtonGrid::updateAffordability(int buildingBlocks)
+void BuildButtonGrid::updateAffordability()
 {
+    const int buildingBlocks = m_sim->getBuildingBlocksStock();
+
+    // If the currently selected tool can no longer be afforded, exit builder mode
+    // before recomputing button states so it does not stay selected. Clearing the
+    // active index first lets the loop below disable the now-unaffordable button.
+    if (m_activeIndex)
+    {
+        const BuildingType activeType = m_types[*m_activeIndex];
+        const std::map<BuildingType, int>::const_iterator it = m_costs.find(activeType);
+        const int cost = (it != m_costs.end()) ? it->second : 0;
+        if (buildingBlocks < cost)
+        {
+            clearActiveButton();
+            EventManager::getInstance()->sendEventImmediately(
+                std::make_shared<ExitBuilderModeRequestedEvent>());
+        }
+    }
+
     for (std::size_t i = 0; i < m_buttons.size(); ++i)
     {
         const BuildingType type = m_types[i];
         const std::map<BuildingType, int>::const_iterator it = m_costs.find(type);
         const int cost = (it != m_costs.end()) ? it->second : 0;
-        m_buttons[i]->setEnabled(buildingBlocks >= cost || m_activeIndex == static_cast<int>(i));
+        m_buttons[i]->setEnabled(buildingBlocks >= cost || m_activeIndex == i);
     }
 }
 
 void BuildButtonGrid::clearActiveButton()
 {
-    if (m_activeIndex >= 0 && m_activeIndex < static_cast<int>(m_buttons.size()))
+    if (m_activeIndex)
     {
-        m_buttons[static_cast<std::size_t>(m_activeIndex)]->setChecked(false);
+        m_buttons[*m_activeIndex]->setChecked(false);
     }
-    m_activeIndex = -1;
+    m_activeIndex.reset();
 }
 
 void BuildButtonGrid::onBuildButton(int index)
@@ -101,8 +124,9 @@ void BuildButtonGrid::onBuildButton(int index)
     {
         return;
     }
+    const std::size_t idx = static_cast<std::size_t>(index);
 
-    if (m_activeIndex == index)
+    if (m_activeIndex == idx)
     {
         clearActiveButton();
         EventManager::getInstance()->sendEventImmediately(
@@ -110,15 +134,15 @@ void BuildButtonGrid::onBuildButton(int index)
         return;
     }
 
-    if (m_activeIndex >= 0 && m_activeIndex < static_cast<int>(m_buttons.size()))
+    if (m_activeIndex)
     {
-        m_buttons[static_cast<std::size_t>(m_activeIndex)]->setChecked(false);
+        m_buttons[*m_activeIndex]->setChecked(false);
     }
 
-    m_activeIndex = index;
-    m_buttons[static_cast<std::size_t>(index)]->setChecked(true);
+    m_activeIndex = idx;
+    m_buttons[idx]->setChecked(true);
     EventManager::getInstance()->sendEventImmediately(
-        std::make_shared<BuildingTypeSelectedEvent>(m_types[static_cast<std::size_t>(index)]));
+        std::make_shared<BuildingTypeSelectedEvent>(m_types[idx]));
 }
 
 void BuildButtonGrid::handleEvent(std::shared_ptr<const BuilderModeExitedEvent> /*event*/)
@@ -126,6 +150,11 @@ void BuildButtonGrid::handleEvent(std::shared_ptr<const BuilderModeExitedEvent>
     clearActiveButton();
 }
 
+void BuildButtonGrid::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> /*event*/)
+{
+    updateAffordability();
+}
+
 void BuildButtonGrid::handleEvent(std::shared_ptr<const DemolishModeChangedEvent> event)
 {
     m_demolishButton->setChecked(event->active);

src/ui/BuildButtonGrid.h

@@ -1,46 +1,56 @@
 #pragma once
 
 #include <map>
+#include <optional>
 #include <vector>
 
 #include <QWidget>
 
 #include "BuilderModeExitedEvent.h"
 #include "BuildHotkeyPressedEvent.h"
+#include "BuildingBlocksChangedEvent.h"
 #include "BuildingType.h"
 #include "DemolishModeChangedEvent.h"
 #include "EventHandler.h"
 #include "GameConfig.h"
 
 class QPushButton;
+class Simulation;
 
 class BuildButtonGrid : public QWidget,
                         public CombinedEventHandler<BuilderModeExitedEvent,
                                                     DemolishModeChangedEvent,
-                                                    BuildHotkeyPressedEvent>
+                                                    BuildHotkeyPressedEvent,
+                                                    BuildingBlocksChangedEvent>
 {
     Q_OBJECT
 
 public:
-    BuildButtonGrid(const GameConfig* config, QWidget* parent = nullptr);
+    BuildButtonGrid(Simulation* sim, const GameConfig* config, QWidget* parent = nullptr);
     ~BuildButtonGrid() override;
 
-    void updateAffordability(int buildingBlocks);
     void clearActiveButton();
 
 private:
+    // Re-evaluates which build buttons are enabled from the current building block
+    // stock (read from the simulation). If the currently selected tool can no longer
+    // be afforded, it exits builder mode so the button does not stay selected.
+    void updateAffordability();
+
     void handleEvent(std::shared_ptr<const BuilderModeExitedEvent> event) override;
     void handleEvent(std::shared_ptr<const DemolishModeChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const BuildHotkeyPressedEvent> event) override;
+    void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;
 
 private slots:
     void onBuildButton(int index);
 
 private:
+    Simulation*                      m_sim;
     const GameConfig*                m_config;
     std::vector<BuildingType>        m_types;
     std::vector<QPushButton*>        m_buttons;
     std::map<BuildingType, int>      m_costs;
-    int                              m_activeIndex;
+    std::optional<std::size_t>       m_activeIndex;
     QPushButton*                     m_demolishButton;
 };

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
@@ -21,6 +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

src/ui/GameWorldView.h

@@ -76,7 +76,7 @@ public:
                   const ParsedReplay* replay, QWidget* parent = nullptr);
     ~GameWorldView() override;
 
-    double gameSpeed() const;
+    double getGameSpeed() const;
     bool isDebugDrawEnabled() const;
     void resetFrameTimer();
     void setGameSpeed(double multiplier);
@@ -115,6 +115,7 @@ 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);
@@ -130,22 +131,37 @@ private:
     void drawBeams(QPainter& painter);
     void drawOverlays(QPainter& painter);
     void drawScreenSpace(QPainter& painter);
+    // Vignette-style border shown while the game is paused (speed 0x, REQ-UI-PAUSE-BORDER)
+    // to make the paused state hard to miss: a black frame whose alpha fades from 50% at
+    // the viewport edges to 0% toward the center.
+    void drawPauseBorder(QPainter& painter);
+    // Vignette-style border shown while demolish mode is active (REQ-UI-DEMOLISH-BORDER),
+    // tinted with the demolish overlay color (including its configured alpha) from
+    // visuals.toml instead of black.
+    void drawDemolishBorder(QPainter& painter);
+    // Shared drawing for the pause/demolish vignettes: a mitred picture-frame border
+    // whose alpha fades from `edgeColor` (with its own alpha) at the viewport edge to
+    // fully transparent toward the center.
+    void drawVignetteBorder(QPainter& painter, const QColor& edgeColor);
     void drawReplayOverlay(QPainter& painter);
 
-    float    tilePx() const;
-    float    viewportWidthTiles() const;
+    float    getTilePx() const;
+    float    getViewportWidthTiles() 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    getViewLeftTiles() const;
     QPointF  worldToWidget(QVector2D worldPos) const;
     QPointF  tileToWidget(QPoint tile) const;
     QPoint   widgetToTile(QPoint widgetPt) const;
     QRectF   tileRect(QPoint tile) const;
-    QRect    viewportRect() const;
+    QRect    getViewportRect() 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;
+    float    getAsteroidLeftEdge() const;
+    float    getEnemyStationRightEdge() const;
     // Horizontal pan speed at a given view-center X, in tiles/s (REQ-UI-SCROLL-SPEED).
     float    panSpeedTilesPerSecondAt(float viewCenterXTiles) const;
     void     clampScroll();
@@ -159,15 +175,24 @@ private:
     std::vector<BuildingId> buildingsInBox(QPoint cornerA, QPoint cornerB) const;
     QVector2D  widgetToWorld(QPoint widgetPt) const;
 
-    void     drawPortGlyph(QPainter& painter, QPoint bodyTile,
-                           Rotation direction, const QColor& color);
+    void     drawPortGlyph(QPainter& painter, QPoint tile,
+                           Rotation direction, const QColor& color,
+                           bool centered);
 
     void     drawBuildingGhost(QPainter& painter, BuildingType type,
-                               QPoint anchorTile, Rotation rotation, bool valid);
+                               QPoint anchorTile, Rotation rotation, bool valid,
+                               bool showPortTargetGlyphs);
 
     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);
 
@@ -211,6 +236,7 @@ private:
     std::mt19937  m_rng;
     double        m_gameSpeedMultiplier;
     double        m_prevNonZeroSpeed;
+    // World-X (tiles) at the center of the viewport (see getViewLeftTiles()).
     float         m_scrollXTiles;
 
     QTimer* m_renderTimer;
@@ -249,6 +275,7 @@ private:
 
     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;

src/ui/HeaderBar.cpp

@@ -17,7 +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);
@@ -25,8 +25,18 @@ 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);
+    if (config->world.artifactTooltip)
+    {
+        m_artifactsLabel->setToolTip(
+            QString::fromStdString(*config->world.artifactTooltip));
+    }
     m_bossLabel      = new QLabel(tr("Boss Wave #1  Next boss: 5:00"), this);
     layout->addWidget(m_timeLabel);
     layout->addWidget(m_blocksLabel);
@@ -81,7 +91,7 @@ void HeaderBar::handleEvent(std::shared_ptr<const TickAdvancedEvent> event)
 void HeaderBar::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
 {
     m_blocks = event->blocks;
-    m_blocksLabel->setText(tr("Blocks: %1").arg(event->blocks));
+    m_blocksLabel->setText(tr("Building Blocks: %1").arg(event->blocks));
     updateExpandButton();
 }
 
@@ -93,7 +103,7 @@ void HeaderBar::handleEvent(std::shared_ptr<const ExpansionCostChangedEvent> eve
 
 void HeaderBar::updateExpandButton()
 {
-    m_expandButton->setText(tr("Expand: %1 Blocks").arg(m_expansionCost));
+    m_expandButton->setText(tr("Expand: %1 Building Blocks").arg(m_expansionCost));
     m_expandButton->setEnabled(m_blocks >= m_expansionCost);
 }
 

src/ui/HeaderBar.h

@@ -9,6 +9,7 @@
 #include "BuildingBlocksChangedEvent.h"
 #include "EventHandler.h"
 #include "ExpansionCostChangedEvent.h"
+#include "GameConfig.h"
 #include "GameSpeedChangedEvent.h"
 #include "Tick.h"
 #include "TickAdvancedEvent.h"
@@ -27,7 +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:

src/ui/MainWindow.cpp

@@ -14,7 +14,6 @@
 
 #include "BlueprintPanel.h"
 #include "BuildButtonGrid.h"
-#include "BuildingBlocksChangedEvent.h"
 #include "BuildingSystem.h"
 #include "Command.h"
 #include "CommandRequestedEvent.h"
@@ -42,24 +41,42 @@ 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->getConfig(), this);
 
-    m_gameWorldView = new GameWorldView(sim, &sim->config(), &m_visuals, m_configDir,
+    m_gameWorldView = new GameWorldView(sim, &sim->getConfig(), &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);
-    m_blueprintPanel        = new BlueprintPanel(sim, &sim->config(), m_sidePanel);
+    m_selectedBuildingPanel = new SelectedBuildingPanel(sim, &sim->getConfig(), m_sidePanel);
+    m_buildButtonGrid       = new BuildButtonGrid(sim, &sim->getConfig(), m_sidePanel);
+    m_blueprintPanel        = new BlueprintPanel(sim, &sim->getConfig(), m_sidePanel);
 
     sideLayout->addWidget(m_selectedBuildingPanel, 1);
     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) {
@@ -130,19 +147,16 @@ 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);
-}
-
-void MainWindow::handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event)
-{
-    m_buildButtonGrid->updateAffordability(event->blocks);
+    m_dimOverlay->setGeometry(0, 0, totalW, totalH);
 }
 
 void MainWindow::handleEvent(std::shared_ptr<const SchematicChoicesAvailableEvent> event)
 {
-    const double prevSpeed = m_gameWorldView->gameSpeed();
+    const double prevSpeed = m_gameWorldView->getGameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
-    SchematicChoiceDialog dialog(event->choices, m_sim->config().recipes, this);
+    ModalDimScope dim(*m_dimOverlay);
+    SchematicChoiceDialog dialog(event->choices, m_sim->getConfig().recipes, this);
     dialog.exec();
 
     std::shared_ptr<ApplySchematicChoiceCommand> command =
@@ -157,9 +171,10 @@ void MainWindow::handleEvent(std::shared_ptr<const SchematicChoicesAvailableEven
 
 void MainWindow::handleEvent(std::shared_ptr<const EscapeMenuRequestedEvent> /*event*/)
 {
-    const double prevSpeed = m_gameWorldView->gameSpeed();
+    const double prevSpeed = m_gameWorldView->getGameSpeed();
     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 +193,7 @@ 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)
         {
@@ -206,20 +222,51 @@ 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();
+    const double prevSpeed = m_gameWorldView->getGameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
+    std::set<std::string> unlockedModuleIds;
+    for (const ModuleDef& def : m_sim->getConfig().modules.modules)
+    {
+        if (m_sim->isModuleSchematicUnlocked(def.id))
+        {
+            unlockedModuleIds.insert(def.id);
+        }
+    }
+
+    ModalDimScope dim(*m_dimOverlay);
+    ShipLayoutDialog dialog(&m_sim->getConfig(), schematicId, currentLayout,
+                            m_layoutBlueprints,
+                            std::move(unlockedModuleIds),
+                            m_gameWorldView->isDebugDrawEnabled(),
+                            this);
+    if (dialog.exec() == QDialog::Accepted && dialog.getResult().has_value())
+    {
+        std::shared_ptr<SetShipLayoutCommand> command =
+            std::make_shared<SetShipLayoutCommand>();
+        command->id     = shipyardId;
+        command->layout = *dialog.getResult();
+        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);
+    const Building* b = m_sim->getBuildings().findBuilding(event->shipyardId);
     const ConstructionSite* s =
-        b ? nullptr : m_sim->buildings().findSite(event->shipyardId);
+        b ? nullptr : m_sim->getBuildings().findSite(event->shipyardId);
     if (!b && !s)
     {
-        m_gameWorldView->setGameSpeed(prevSpeed);
-        m_gameWorldView->resetFrameTimer();
         return;
     }
 
@@ -233,44 +280,19 @@ 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)
 {
-    const double prevSpeed = m_gameWorldView->gameSpeed();
+    const double prevSpeed = m_gameWorldView->getGameSpeed();
     m_gameWorldView->setGameSpeed(0.0);
 
     // A construction site has no Building yet; fall back to its site record so
     // the recipe/schematic can be chosen before it is built (REQ-BLD-SITE-CONFIG).
-    const Building* b = m_sim->buildings().findBuilding(event->buildingId);
+    const Building* b = m_sim->getBuildings().findBuilding(event->buildingId);
     const ConstructionSite* s =
-        b ? nullptr : m_sim->buildings().findSite(event->buildingId);
+        b ? nullptr : m_sim->getBuildings().findSite(event->buildingId);
     if (!b && !s)
     {
         m_gameWorldView->setGameSpeed(prevSpeed);
@@ -278,13 +300,23 @@ 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());
+        buildRecipeSelectionOptions(type, *m_sim, m_sim->getConfig());
     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())
     {
@@ -293,19 +325,37 @@ 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*/)
 {
-    const Tick tick = m_sim->currentTick();
+    const Tick tick = m_sim->getCurrentTick();
     const int totalSeconds = static_cast<int>(ticksToSeconds(tick));
     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 +374,7 @@ 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)
         {
@@ -346,11 +397,12 @@ void MainWindow::handleEvent(std::shared_ptr<const GameOverEvent> /*event*/)
 
 void MainWindow::handleEvent(std::shared_ptr<const WinEvent> /*event*/)
 {
-    const Tick tick = m_sim->currentTick();
+    const Tick tick = m_sim->getCurrentTick();
     const int totalSeconds = static_cast<int>(ticksToSeconds(tick));
     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 +419,7 @@ 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

@@ -6,15 +6,16 @@
 
 #include <QWidget>
 
-#include "BuildingBlocksChangedEvent.h"
 #include "BuildingId.h"
 #include "EscapeMenuRequestedEvent.h"
 #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"
@@ -30,8 +31,7 @@ class QCloseEvent;
 class QResizeEvent;
 
 class MainWindow : public QWidget,
-                   public CombinedEventHandler<BuildingBlocksChangedEvent,
-                                               SchematicChoicesAvailableEvent,
+                   public CombinedEventHandler<SchematicChoicesAvailableEvent,
                                                GameOverEvent,
                                                WinEvent,
                                                EscapeMenuRequestedEvent,
@@ -50,13 +50,18 @@ protected:
     void closeEvent(QCloseEvent* event) override;
 
 private:
-    void handleEvent(std::shared_ptr<const BuildingBlocksChangedEvent> event) override;
     void handleEvent(std::shared_ptr<const SchematicChoicesAvailableEvent> event) override;
     void handleEvent(std::shared_ptr<const GameOverEvent> event) override;
     void handleEvent(std::shared_ptr<const WinEvent> event) override;
     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 +74,7 @@ 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

@@ -23,7 +23,7 @@ QString itemLine(const std::string& itemId, int amount)
 {
     return QStringLiteral("  ")
         + QString::fromStdString(toDisplayName(itemId))
-        + QStringLiteral(" ×") + QString::number(amount);
+        + QStringLiteral(" x ") + QString::number(amount);
 }
 
 QString shipTooltip(const ShipDef& def)
@@ -44,6 +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")

src/ui/RecipeTooltip.cpp

@@ -13,7 +13,7 @@ QString itemLine(const std::string& itemId, int amount)
 {
     return QStringLiteral("  ")
         + QString::fromStdString(toDisplayName(itemId))
-        + QStringLiteral(" ×") + QString::number(amount);
+        + QStringLiteral(" x ") + QString::number(amount);
 }
 
 }  // namespace

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"
@@ -37,6 +38,7 @@
 #include "RecipeSelectionDialog.h"
 #include "RecipeSelectionRequestedEvent.h"
 #include "Rotation.h"
+#include "ScrapSystem.h"
 #include "ShipLayoutPreview.h"
 #include "Simulation.h"
 #include "WeaponComponent.h"
@@ -46,6 +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;
@@ -78,6 +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
@@ -171,6 +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();
@@ -187,6 +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();
 }
@@ -219,6 +252,7 @@ void SelectedBuildingPanel::hideAllWidgets()
     m_filterBLabel->hide();
     m_filterBList->hide();
     m_buffersLabel->hide();
+    m_scrapLabel->hide();
 }
 
 void SelectedBuildingPanel::clearContent()
@@ -240,8 +274,8 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
     m_singleBuildingId = id;
     hideAllWidgets();
 
-    const Building*         b = m_sim->buildings().findBuilding(id);
-    const ConstructionSite* s = b ? nullptr : m_sim->buildings().findSite(id);
+    const Building*         b = m_sim->getBuildings().findBuilding(id);
+    const ConstructionSite* s = b ? nullptr : m_sim->getBuildings().findSite(id);
     if (!b && !s)
     {
         buildEmpty();
@@ -265,7 +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);
@@ -319,12 +353,12 @@ void SelectedBuildingPanel::buildSingle(BuildingId id)
         std::optional<BeltSystem::SplitterInfo> info;
         if (m_singleIsSite)
         {
-            info = m_sim->buildings().getSiteSplitterInfo(id);
+            info = m_sim->getBuildings().getSiteSplitterInfo(id);
         }
         else
         {
             m_splitterTile = anchor;
-            info = m_sim->belts().getSplitterInfo(m_splitterTile);
+            info = m_sim->getBelts().getSplitterInfo(m_splitterTile);
         }
         buildSplitterFilters(info);
     }
@@ -363,7 +397,7 @@ void SelectedBuildingPanel::refreshSiteProgress(const ConstructionSite* s)
         if (def && def->constructionTimeSeconds > 0)
         {
             const Tick duration = secondsToTicks(def->constructionTimeSeconds);
-            const Tick elapsed  = m_sim->currentTick() - (s->completesAt - duration);
+            const Tick elapsed  = m_sim->getCurrentTick() - (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);
@@ -383,6 +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())
@@ -436,13 +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)
         {
@@ -454,13 +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)
         {
@@ -469,41 +524,51 @@ 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->getCurrentTick();
+                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");
         }
     }
@@ -522,11 +587,21 @@ void SelectedBuildingPanel::updateShipyardLayoutWidgets(
     const std::string& recipeId,
     const std::optional<ShipLayoutConfig>& shipLayout)
 {
-    const ShipDef* shipDef = (type == BuildingType::Shipyard)
-        ? findShipDef(recipeId)
-        : nullptr;
+    // 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;
+    }
 
-    if (shipDef && !shipDef->layout.empty())
+    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 (shipLayout.has_value())
@@ -535,14 +610,16 @@ void SelectedBuildingPanel::updateShipyardLayoutWidgets(
         }
         m_layoutPreview->setShipAndLayout(
             shipDef->layout, layout, &m_config->modules.modules);
-        m_layoutPreview->show();
-        m_configureLayoutBtn->show();
     }
     else
     {
-        m_layoutPreview->hide();
-        m_configureLayoutBtn->hide();
+        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
@@ -582,6 +659,13 @@ void SelectedBuildingPanel::handleEvent(
 
 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();
@@ -589,7 +673,7 @@ void SelectedBuildingPanel::refreshSelectionDisplay(RefreshReason reason)
     }
 
     if (m_singleBuildingId == kInvalidBuildingId) { return; }
-    const Building* b = m_sim->buildings().findBuilding(m_singleBuildingId);
+    const Building* b = m_sim->getBuildings().findBuilding(m_singleBuildingId);
     if (b)
     {
         if (m_titleLabel->text().startsWith(tr("(Building) ")))
@@ -602,7 +686,7 @@ void SelectedBuildingPanel::refreshSelectionDisplay(RefreshReason reason)
         }
         return;
     }
-    const ConstructionSite* s = m_sim->buildings().findSite(m_singleBuildingId);
+    const ConstructionSite* s = m_sim->getBuildings().findSite(m_singleBuildingId);
     if (s)
     {
         // A periodic tick only advances construction progress, so update just the
@@ -636,13 +720,13 @@ void SelectedBuildingPanel::buildMulti(const std::vector<BuildingId>& ids)
     std::map<BuildingType, int> counts;
     for (BuildingId id : ids)
     {
-        const Building* b = m_sim->buildings().findBuilding(id);
+        const Building* b = m_sim->getBuildings().findBuilding(id);
         if (b)
         {
             counts[b->type]++;
             continue;
         }
-        const ConstructionSite* s = m_sim->buildings().findSite(id);
+        const ConstructionSite* s = m_sim->getBuildings().findSite(id);
         if (s)
         {
             counts[s->type]++;
@@ -650,6 +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)
     {
@@ -659,7 +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();
 
@@ -698,7 +791,7 @@ void SelectedBuildingPanel::buildSplitterFilters(
         return;
     }
 
-    const std::vector<std::string> items = allItemIds();
+    const std::vector<std::string> items = getAllItemIds();
 
     auto populateList = [&](QListWidget* list, QLabel* label,
                             const QString& dirLabel,
@@ -773,7 +866,7 @@ void SelectedBuildingPanel::onSplitterFilterChanged()
     }
 }
 
-std::vector<std::string> SelectedBuildingPanel::allItemIds() const
+std::vector<std::string> SelectedBuildingPanel::getAllItemIds() const
 {
     std::set<std::string> seen;
     for (const RecipeDef& recipe : m_config->recipes.recipes)
@@ -795,7 +888,7 @@ void SelectedBuildingPanel::onClearBelt()
     std::vector<QPoint> tiles;
     for (BuildingId id : m_selectedBuildingIds)
     {
-        const Building* b = m_sim->buildings().findBuilding(id);
+        const Building* b = m_sim->getBuildings().findBuilding(id);
         if (b && isBeltLike(b->type))
         {
             for (const QPoint& cell : b->bodyCells)
@@ -820,9 +913,12 @@ 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();
+        EntityAdmin& admin = m_sim->getAdmin();
         entt::entity entity = *m_selectedEntity;
 
         if (!admin.isValid(entity))
@@ -848,7 +944,7 @@ void SelectedBuildingPanel::handleEvent(std::shared_ptr<const EntitySelectedEven
 
 void SelectedBuildingPanel::buildEntityShip(entt::entity entity)
 {
-    EntityAdmin& admin = m_sim->admin();
+    EntityAdmin& admin = m_sim->getAdmin();
     const ShipIdentityComponent& identity = admin.get<ShipIdentityComponent>(entity);
     const HealthComponent& health = admin.get<HealthComponent>(entity);
 
@@ -858,6 +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)
@@ -878,10 +976,14 @@ void SelectedBuildingPanel::buildEntityShip(entt::entity entity)
 
 void SelectedBuildingPanel::buildEntityStation(entt::entity entity)
 {
-    EntityAdmin& admin = m_sim->admin();
+    EntityAdmin& admin = m_sim->getAdmin();
     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;
@@ -917,7 +1019,7 @@ void SelectedBuildingPanel::refreshEntityStats()
 {
     if (!m_selectedEntity.has_value()) { return; }
 
-    EntityAdmin& admin = m_sim->admin();
+    EntityAdmin& admin = m_sim->getAdmin();
     entt::entity entity = *m_selectedEntity;
 
     if (!admin.isValid(entity))
@@ -937,6 +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))
     {
@@ -957,6 +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->getScraps().getAllScrapInfo())
+    {
+        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

@@ -18,6 +18,7 @@
 #include "GameConfig.h"
 #include "PlayerCommandsAppliedEvent.h"
 #include "RecipesConfig.h"
+#include "ScrapSelectionChangedEvent.h"
 #include "SelectionChangedEvent.h"
 #include "ShipLayout.h"
 #include "ShipsConfig.h"
@@ -37,6 +38,7 @@ class SelectedBuildingPanel : public QWidget,
                                                            PlayerCommandsAppliedEvent,
                                                            EntitySelectedEvent,
                                                            SelectionChangedEvent,
+                                                           ScrapSelectionChangedEvent,
                                                            DebugDrawToggledEvent>
 {
     Q_OBJECT
@@ -51,6 +53,7 @@ private:
     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:
@@ -77,6 +80,8 @@ private:
     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,
@@ -85,7 +90,7 @@ private:
     void buildSplitterFilters(const std::optional<BeltSystem::SplitterInfo>& info);
     const RecipeDef* findRecipe(const Building* b) const;
     const ShipDef*   findShipDef(const std::string& id) const;
-    std::vector<std::string> allItemIds() const;
+    std::vector<std::string> getAllItemIds() const;
 
     Simulation*        m_sim;
     const GameConfig*  m_config;
@@ -115,6 +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);
 
@@ -574,7 +578,7 @@ ShipLayoutDialog::ShipLayoutDialog(const GameConfig* config,
     });
 }
 
-std::optional<ShipLayoutConfig> ShipLayoutDialog::result() const
+std::optional<ShipLayoutConfig> ShipLayoutDialog::getResult() const
 {
     return m_result;
 }

src/ui/ShipLayoutDialog.h

@@ -30,7 +30,7 @@ public:
                      bool debugDraw,
                      QWidget* parent = nullptr);
 
-    std::optional<ShipLayoutConfig> result() const;
+    std::optional<ShipLayoutConfig> getResult() const;
 
 protected:
     void keyPressEvent(QKeyEvent* event) override;

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

@@ -49,6 +49,8 @@ struct OverlayVisuals
     QColor tileHighlight;
     QColor selectedOutline;
     QColor copyConfig;
+    QColor lockedAsteroid;
+    QColor modalDim;
 };
 
 struct ToastVisuals

src/ui/VisualsLoader.cpp

@@ -225,6 +225,8 @@ VisualsConfig VisualsLoader::load(const std::string& path)
         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