Add supply auto-purchase and preserve save recovery state

tests/s1/test_path_snapshot_transit_guard.gd

@@ -0,0 +1,48 @@
+extends SceneTree
+## A corrupt transit ID must reject the entire save projection without losing
+## real cabin occupants or making the infrastructure collision check fail open.
+var checks := 0
+var failures := 0
+
+
+func _initialize() -> void:
+	call_deferred("run")
+
+
+func expect(ok: bool, label: String) -> void:
+	checks += 1
+	if not ok:
+		failures += 1
+		push_error(label)
+
+
+func run() -> void:
+	var path := PathService.new()
+	var cells: Array[Vector3i] = [Vector3i.ZERO, Vector3i(0, 1, 0)]
+	expect(path.rebuild_graph(cells), "build a normal graph")
+	expect(path.configure_elevator(&"lift", cells[0], cells[1], {&"cabin_capacity": 2}), "configure a real cabin")
+	for actor: StringName in [&"guest:a", &"guest:b"]:
+		expect(path.project_actor_position(actor, cells[0], 10), "position cabin passenger")
+		expect(path.enqueue_elevator_request(&"lift", {
+			&"request_id": StringName("ride." + String(actor)), &"unit_id": actor,
+			&"floor_from": 0, &"floor_to": 1, &"enqueued_at": 10,
+		})[&"ok"], "queue real passenger")
+	expect(path.dequeue_elevator_boarding(&"lift", 0, 11, 2).size() == 2, "board both passengers")
+	var valid: Dictionary = path.create_snapshot()
+	expect(valid[&"transit_actor_ids"].size() == 2, "normal save keeps both cabin occupants")
+	for bad_id: Variant in [123, true, 1.25, Vector3i(3, 2, 1), null]:
+		path._transit_actor_ids[bad_id] = true
+		var before := var_to_bytes(path._transit_actor_ids)
+		var saved: Dictionary = path.create_snapshot()
+		expect(saved.is_empty(), "unsupported transit ID rejects the whole projection")
+		expect(var_to_bytes(path._transit_actor_ids) == before, "refusal preserves all transit IDs")
+		expect(FacilityInfrastructureProjector._has_managed_namespace_collision(SpatialSubslotService.new(), path, {}), "consumer refuses rejected snapshot")
+		saved[&"caller"] = true
+		expect(path.create_snapshot().is_empty(), "repeat refusal returns a new empty projection")
+		path._transit_actor_ids.erase(bad_id)
+		expect(var_to_bytes(path.create_snapshot()) == var_to_bytes(valid), "correction recovers both original occupants")
+	var restored := PathService.new()
+	expect(restored.restore_snapshot(valid) and restored.rebuild_graph(cells), "save restores real passenger references")
+	expect(var_to_bytes(restored.create_snapshot()) == var_to_bytes(valid), "restored full save matches original")
+	print("Path snapshot transit guard: %d checks, %d failures" % [checks, failures])
+	quit(1 if failures else 0)

tests/s1/test_path_snapshot_transit_guard.gd.uid

@@ -0,0 +1 @@
+uid://cqhxb665hdby6

tests/s1/test_runtime_infrastructure_integration.gd

@@ -1,6 +1,6 @@
 extends SceneTree
 
-const RUNTIME_SNAPSHOT_VERSION := 13
+const RUNTIME_SNAPSHOT_VERSION := 14
 const INFRASTRUCTURE_SNAPSHOT_KEYS: Array[StringName] = [
 	&"excavation",
 	&"spatial_subslots",
@@ -186,7 +186,7 @@ func _test_runtime_surface(fixture: Dictionary) -> bool:
 	var snapshot: Dictionary = runtime.create_snapshot()
 	var runtime_data: Dictionary = snapshot[&"systems"][&"runtime"]
 	var current_version := int(runtime_data.get(&"runtime_schema_version", -1)) == RUNTIME_SNAPSHOT_VERSION
-	_expect(current_version, "Runtime emits schema v13 with infrastructure and weather state")
+	_expect(current_version, "Runtime emits schema v14 with infrastructure and weather state")
 	ready = ready and current_version
 	for key: StringName in INFRASTRUCTURE_SNAPSHOT_KEYS:
 		var valid_dictionary := runtime_data.get(key, null) is Dictionary
@@ -923,7 +923,7 @@ func _test_v5_proxy_migration_determinism() -> void:
 	_expect(first_runtime.restore_snapshot(legacy), "v5 proxy snapshot migrates through Runtime restore")
 	var first_migrated: Dictionary = first_runtime.create_snapshot()
 	_expect(
-		int(first_migrated[&"systems"][&"runtime"][&"runtime_schema_version"]) == 13,
+		int(first_migrated[&"systems"][&"runtime"][&"runtime_schema_version"]) == 14,
 		"v5 migration is immediately re-emitted as v9"
 	)
 	_expect(