fix: improve maintenance and synchronize live conversations

backend/app/api/widget.py

@@ -27,7 +27,6 @@ from urllib.parse import urlparse
 from app.models.agent import Agent
 from app.models.customer import Customer
 from app.models.widget import Widget
-from app.models.user import User
 
 from app.core.auth import get_current_user
 from app.database import get_db