修改引用逻辑，修改长期记忆bug

app/nodes/finalize.py

@@ -4,15 +4,13 @@
 """
 
 from typing import Any, Dict
-from langgraph.runtime import Runtime
 from langgraph.config import get_stream_writer
 
 # 本地模块
-from app.graph.state import MessagesState, GraphContext
+from app.graph.state import MessagesState
 from app.utils.logging import log_state_change
 from app.logger import info, error
 
-
 from langchain_core.runnables.config import RunnableConfig
 
 async def finalize_node(state: MessagesState, config: RunnableConfig) -> Dict[str, Any]: