Implement config-driven unlock groups

Lift unlocking into first-class unlock groups defined in unlocks.toml, so
one defence-station drop can grant a bundle of ships/modules/buildings/
recipes at once (e.g. the salvager module + salvage bay), and buildings
can now be locked at game start and unlocked via a drop.

Config:
- New UnlocksConfig + ConfigLoader::loadUnlocks + validateUnlocks (unknown/
  duplicate/non-assembler grants, unknown requires, empty group all fail load).
- Drop unlock_at_station_level/unlock_requires from ship/module/recipe defs;
  add unlocked_at_start bool to recipes for graph-unreachable base recipes.

Simulation:
- Track awarded groups + per-building unlock state; an item starts unlocked
  iff no group grants it. Rework generateSchematicChoices/applySchematicChoice
  to operate on groups (grant all members at once). Extend state checksum.
- isBuildingUnlocked query; tryPlaceBuilding rejects locked types.

UI:
- Build-menu buttons for locked buildings start hidden, revealed via a new
  UnlockedBuildingsChangedEvent (emitted from GameWorldView's poll loop).
- Schematic choice dialog lists a group's granted items.
- Blueprint placement excludes locked building types (REQ-LOCK-UI-BLUEPRINT).

Data: unlocks.toml (app + test) reproduces the prior per-item gates as
singleton groups and adds salvage_operations (salvager + salvage_bay, lvl 1)
and reprocessing (reprocessing_plant, lvl 2).

Tests: rewrote unlock/config/recipe-schematic/artifact/wave/shipyard tests
for the group model; added UnlockGroupTest. All 443 cases pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y7N59FsLA5e2kuVdqe4Uhc

bin/test/data/config/modules.toml

@@ -1,7 +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}]
 production_time_seconds = 3
@@ -13,7 +12,6 @@ multiplied_hp = 1.5
 
 [[module]]
 id = "sensor_booster"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "circuit_board", amount = 1}]
 production_time_seconds = 2
@@ -25,7 +23,6 @@ added_sensor_range_m = 100
 
 [[module]]
 id = "weapon_upgrade"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}, {item = "circuit_board", amount = 1}]
 production_time_seconds = 4
@@ -37,7 +34,6 @@ multiplied_damage = 1.2
 
 [[module]]
 id = "laser_cannon"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}]
 production_time_seconds = 5
@@ -51,7 +47,6 @@ attack_rate_hz = 2.0
 
 [[module]]
 id = "salvager"
-unlock_at_station_level = -1
 surface_mask = ["OO"]
 materials = [{item = "iron_ingot", amount = 2}]
 production_time_seconds = 5
@@ -65,7 +60,6 @@ collection_rate_hz = 0.5
 
 [[module]]
 id = "repair_tool"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "circuit_board", amount = 2}]
 production_time_seconds = 5
@@ -79,7 +73,6 @@ repair_range_m = 800
 
 [[module]]
 id = "weapon_primer"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}]
 production_time_seconds = 4
@@ -91,7 +84,6 @@ multiplied_attack_rate_hz = 1.2
 
 [[module]]
 id = "weapon_stabilizer"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}]
 production_time_seconds = 4
@@ -104,7 +96,6 @@ multiplied_attack_rate_hz = 0.8
 
 [[module]]
 id = "afterburner"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}]
 production_time_seconds = 2
@@ -117,7 +108,6 @@ added_main_acceleration_mpss = 60
 
 [[module]]
 id = "maneuvering_thrusters"
-unlock_at_station_level = -1
 surface_mask = ["O"]
 materials = [{item = "iron_ingot", amount = 1}]
 production_time_seconds = 2