fix delete user conversation not being async

src/agent.py

@@ -672,8 +672,8 @@ async def async_langflow_chat_stream(
             )
 
 
-def delete_user_conversation(user_id: str, response_id: str) -> bool:
-    """Delete a conversation for a user from both memory and persistent storage"""
+async def delete_user_conversation(user_id: str, response_id: str) -> bool:
+    """Delete a conversation for a user from both memory and persistent storage (async, non-blocking)"""
     deleted = False
 
     try:

src/services/chat_service.py

@@ -595,7 +595,7 @@ class ChatService:
         try:
             # Delete from local conversation storage
             from agent import delete_user_conversation
-            local_deleted = delete_user_conversation(user_id, session_id)
+            local_deleted = await delete_user_conversation(user_id, session_id)
 
             # Delete from Langflow using the monitor API
             langflow_deleted = await self._delete_langflow_session(session_id)