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")