fix: 简化清空逻辑 - 空消息列表即清空

core/client.py

@@ -78,7 +78,7 @@ class BackendClient:
         packet = Packet(
             id=self._next_id(),
             type=PacketType.SAVE_HISTORY,
-            body={"messages": [{"action": "clear"}]}
+            body={"messages": []}
         )
         return self._server.send(packet).body
     

core/server.py

@@ -345,7 +345,7 @@ class BackendServer:
 
     def _handle_save_history(self, body: Dict) -> Dict:
         messages = body.get("messages", [])
-        if messages and messages[0].get("action") == "clear":
+        if not messages:
             self._graph.clear_chat_records()
             return {"status": "history_cleared"}
         result = self._graph.save_chat_records(messages)