fix: improve maintenance and synchronize live conversations

backend/app/api/analytics.py

@@ -26,8 +26,7 @@ from app.models.rating import Rating
 from app.models.session_to_agent import SessionToAgent, SessionStatus
 from app.models.chat_history import ChatHistory
 from datetime import datetime, timedelta, timezone
-from sqlalchemy import func, and_, or_, desc, distinct, case
-from typing import Optional, List
+from sqlalchemy import func, and_, desc, case
 from app.core.logger import get_logger
 from uuid import UUID