fix: sqlite list users error (#384)

fix: sqlite users error

Author: fridayL

src/memos/mem_user/persistent_user_manager.py

@@ -177,15 +177,15 @@ def delete_user_config(self, user_id: str) -> bool:
         finally:
             session.close()
 
-    def list_user_configs(self) -> dict[str, MOSConfig]:
+    def list_user_configs(self, limit: int = 1) -> dict[str, MOSConfig]:
         """List all user configurations.
 
         Returns:
             Dict[str, MOSConfig]: Dictionary mapping user_id to MOSConfig.
         """
         session = self._get_session()
         try:
-            user_configs = session.query(UserConfig).all()
+            user_configs = session.query(UserConfig).limit(limit).all()
             result = {}
 
             for user_config in user_configs: