修改引用逻辑，修改长期记忆bug

app/agent/prompts.py

@@ -1,6 +1,5 @@
 # app/prompts.py
 from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
-from langchain_core.tools import BaseTool
 
 def create_system_prompt(tools: list = None) -> ChatPromptTemplate:
     """
@@ -11,7 +10,7 @@ def create_system_prompt(tools: list = None) -> ChatPromptTemplate:
         tool_descs = []
         for tool in tools:
             # 提取工具名称和描述的第一行
-            name = getattr(tool, 'name', tool.__name__)
+            name = getattr(tool, 'name', None) or getattr(tool, '__name__', 'unknown_tool')
             desc = (tool.description or "").split('\n')[0]
             tool_descs.append(f"- {name}: {desc}")
         tools_section = "\n".join(tool_descs)