refactor: move resource authority into simulation

tests/jajce_world_scaffold_test.gd

@@ -87,11 +87,26 @@ func _run() -> void:
 				"Jajce navigation path should exist from %s to %s" % [origin, destination]
 			)
 
-	var selected := ResourceNode.find_available(&"gather_food", 777, Vector3.ZERO)
+	var manager: Node = load("res://simulation/SimulationManager.gd").new()
+	manager.debug_logs = false
+	root.add_child(manager)
+	manager.set_process(false)
+	await process_frame
+	var selected: ResourceNode = manager.acquire_resource_target(
+		&"gather_food",
+		777,
+		Vector3.ZERO
+	)
 	_check(selected != null, "Target discovery should find Jajce resources without a parent path")
 	if selected != null:
-		_check(selected.reserve(777), "Selected Jajce resource should be reservable")
-		selected.release(777)
+		var selected_state: ResourceStateRecord = manager.get_resource_state(
+			selected.node_id
+		)
+		_check(
+			selected_state.get_reserved_by() == 777,
+			"Selected Jajce resource should be authoritatively reserved"
+		)
+		manager.release_resource(selected.node_id, 777)
 
 	if failures.is_empty():
 		print("[TEST] Jajce scaffold passed: Terrain3D, stable IDs, 24 navigation routes")

tests/resource_node_player_parity_test.gd

@@ -18,22 +18,43 @@ func _run() -> void:
 	var tree := main_scene.get_node("ResourceNodes/Tree_01") as ResourceNode
 	simulation_manager.set_process(false)
 
-	bush.amount_remaining = 1.0
-	_check(bush.reserve(999), "Player contention setup should reserve the bush")
+	var bush_state: ResourceStateRecord = simulation_manager.get_resource_state(
+		bush.node_id
+	)
+	var tree_state: ResourceStateRecord = simulation_manager.get_resource_state(
+		tree.node_id
+	)
+	bush_state.set_amount_remaining(1.0)
+	_check(
+		simulation_manager.reserve_resource(bush.node_id, 999),
+		"Player contention setup should reserve the bush"
+	)
 	player.global_position = bush.interaction_point.global_position
 	var food_before: float = simulation_manager.village.food
 	player.try_interact()
 
-	_check(is_equal_approx(bush.amount_remaining, 0.0), "Player should deplete the nearby bush")
+	_check(
+		is_equal_approx(bush_state.get_amount_remaining(), 0.0),
+		"Player should deplete the nearby bush"
+	)
 	_check(is_equal_approx(simulation_manager.village.food, food_before + 1.0), "Village should receive exactly the bush's remaining food")
-	_check(bush.reserved_by == -1, "Depletion should release the NPC reservation")
+	_check(
+		bush_state.get_reserved_by() == -1,
+		"Depletion should release the NPC reservation"
+	)
 
 	player.global_position = tree.interaction_point.global_position
 	var wood_before: float = simulation_manager.village.wood
-	var tree_before := tree.amount_remaining
+	var tree_before := tree_state.get_amount_remaining()
 	player.try_interact()
 
-	_check(is_equal_approx(tree.amount_remaining, tree_before - tree.yield_per_action), "Player should extract the tree's configured yield")
+	_check(
+		is_equal_approx(
+			tree_state.get_amount_remaining(),
+			tree_before - tree.yield_per_action
+		),
+		"Player should extract the tree's configured yield"
+	)
 	_check(is_equal_approx(simulation_manager.village.wood, wood_before + tree.yield_per_action), "Village should receive exactly the extracted wood")
 
 	if failures.is_empty():

tests/simulation_state_serialization_test.gd

@@ -8,6 +8,7 @@ func _initialize() -> void:
 func _run() -> void:
 	await _test_deterministic_continuation()
 	await _test_resource_state_round_trip()
+	_test_legacy_resource_migration()
 	_test_schema_rejection()
 
 	if failures.is_empty():
@@ -64,33 +65,65 @@ func _test_resource_state_round_trip() -> void:
 		"res://world/resource_nodes/ResourceNode.tscn"
 	).instantiate()
 	resource.node_id = &"SerializationTestBerry"
-	resource.amount_remaining = 9.0
+	resource.initial_amount = 9.0
 	resource.yield_per_action = 2.0
 	root.add_child(resource)
 	await process_frame
 
-	_check(resource.reserve(42), "Resource should accept the test reservation")
-	resource.extract()
-
 	var manager := _create_manager(77)
+	_check(
+		manager.register_resource_node(resource),
+		"Resource presentation should bind to simulation authority"
+	)
+	var resource_state: ResourceStateRecord = manager.get_resource_state(
+		resource.node_id
+	)
+	_check(resource_state.reserve(42), "Resource should accept the test reservation")
+	resource_state.extract()
 	var saved_json: String = manager.serialize_state()
-	resource.extract(5.0)
-	resource.release(42)
-	resource.enabled = false
+	resource.free()
+
+	_check(
+		is_equal_approx(resource_state.get_amount_remaining(), 7.0),
+		"Resource state should survive without its presentation node"
+	)
+	resource_state.extract(5.0)
+	resource_state.release(42)
+	resource_state.set_enabled(false)
 
 	_check(
 		manager.restore_state_from_json(saved_json),
-		"Resource state should restore with the simulation record"
+		"Unloaded resource state should restore with the simulation record"
 	)
+	resource_state = manager.get_resource_state(&"SerializationTestBerry")
 	_check(
-		is_equal_approx(resource.amount_remaining, 7.0),
+		is_equal_approx(resource_state.get_amount_remaining(), 7.0),
 		"Resource amount should round-trip"
 	)
-	_check(resource.reserved_by == 42, "Resource reservation should round-trip")
-	_check(resource.enabled, "Resource enabled state should round-trip")
+	_check(
+		resource_state.get_reserved_by() == 42,
+		"Resource reservation should round-trip"
+	)
+	_check(resource_state.is_enabled(), "Resource enabled state should round-trip")
+
+	var rebound: ResourceNode = load(
+		"res://world/resource_nodes/ResourceNode.tscn"
+	).instantiate()
+	rebound.node_id = &"SerializationTestBerry"
+	rebound.initial_amount = 999.0
+	root.add_child(rebound)
+	await process_frame
+	_check(
+		rebound.state == resource_state,
+		"Reloaded presentation should bind to the existing authoritative record"
+	)
+	_check(
+		is_equal_approx(rebound.get_amount_remaining(), 7.0),
+		"Reloaded presentation must not overwrite authoritative amount"
+	)
 
 	manager.free()
-	resource.free()
+	rebound.free()
 
 func _test_schema_rejection() -> void:
 	var unsupported := JSON.stringify({
@@ -106,6 +139,27 @@ func _test_schema_rejection() -> void:
 		"Non-record JSON should be rejected"
 	)
 
+func _test_legacy_resource_migration() -> void:
+	var migrated := ResourceStateRecord.from_dictionary({
+		"schema_version": 1,
+		"node_id": "legacy_tree",
+		"amount_remaining": 6.0,
+		"reserved_by": 12,
+		"enabled": true
+	})
+	_check(migrated != null, "ResourceStateRecord v1 should migrate explicitly")
+	if migrated == null:
+		return
+	_check(
+		migrated.data["schema_version"] == ResourceStateRecord.SCHEMA_VERSION,
+		"Migrated resource state should use the current nested schema"
+	)
+	_check(
+		is_equal_approx(migrated.get_amount_remaining(), 6.0)
+		and migrated.get_reserved_by() == 12,
+		"Resource migration should preserve mutable authority"
+	)
+
 func _create_manager(seed_value: int) -> Node:
 	var manager: Node = load("res://simulation/SimulationManager.gd").new()
 	manager.simulation_seed = seed_value