fix: improve maintenance and synchronize live conversations

backend/app/models/organization.py

@@ -15,10 +15,9 @@ limitations under the License.
 """
 
 import uuid
-from sqlalchemy import Column, Integer, String, Boolean, DateTime, JSON, func, event
+from sqlalchemy import Column, String, Boolean, DateTime, JSON, func, event
 from sqlalchemy.orm import relationship
 from app.database import Base
-from app.models.role import Role
 from sqlalchemy.dialects.postgresql import UUID
 from app.core.logger import get_logger