fix: improve maintenance and synchronize live conversations

backend/tests/repo/test_chat_repo.py

@@ -23,7 +23,7 @@ from app.models.customer import Customer
 from app.models.agent import Agent, AgentType
 from app.models.session_to_agent import SessionToAgent, SessionStatus
 from app.models.user import User, UserGroup
-from uuid import uuid4, UUID
+from uuid import uuid4
 from app.channels.interactive import from_options
 from app.channels.sent_choices import SENT_CHOICES_ATTRIBUTE, encode_sent_choices
 from app.models.schemas.chat import ChatDetailResponse