refactor: clarify simulation ownership

simulation/state/SimulationStateRecord.gd

@@ -177,6 +177,7 @@ static func _migrate_legacy(legacy_data: Dictionary, version: int) -> Dictionary
 	if version == LEGACY_SCHEMA_VERSION:
 		var village_data: Dictionary = legacy_data.get("village", {})
 		var initial_food := float(village_data.get("food", 0.0))
+		var initial_wood := float(village_data.get("wood", 0.0))
 		migrated["storages"] = [
 			(
 				StorageStateRecord
@@ -185,6 +186,14 @@ static func _migrate_legacy(legacy_data: Dictionary, version: int) -> Dictionary
 					{String(SimulationIds.RESOURCE_FOOD): initial_food}
 				)
 				. to_dictionary()
+			),
+			(
+				StorageStateRecord
+				. create(
+					SimulationIds.STORAGE_VILLAGE_WOODPILE,
+					{String(SimulationIds.RESOURCE_WOOD): initial_wood}
+				)
+				. to_dictionary()
 			)
 		]
 	migrated["economic_events"] = []

simulation/state/StorageStateRecord.gd

@@ -57,10 +57,12 @@ func get_total_amount() -> float:
 	return total
 
 
+func get_available_capacity() -> float:
+	return maxf(float(data["capacity"]) - get_total_amount(), 0.0)
+
+
 func deposit(item_id: StringName, requested_amount: float) -> float:
-	var accepted := minf(
-		maxf(requested_amount, 0.0), maxf(float(data["capacity"]) - get_total_amount(), 0.0)
-	)
+	var accepted := minf(maxf(requested_amount, 0.0), get_available_capacity())
 	if accepted <= 0.0:
 		return 0.0
 	data["amounts"][String(item_id)] = get_amount(item_id) + accepted