fix: improve maintenance and synchronize live conversations

backend/app/api/workflow_node.py

@@ -14,9 +14,9 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
-from fastapi import APIRouter, Depends, HTTPException, status
+from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy.orm import Session
-from typing import List, Dict, Any, Optional
+from typing import List, Dict, Any
 from uuid import UUID
 from pydantic import BaseModel
 from app.core.logger import get_logger