* implement delete user conversation on agent
* format
* implement delete session endpoint
* implement delete session on persistence services
* added deletion of sessions and added fetch sessions with query instead of with useEffect
* removed unused texts
* implemented dropdown menu on conversations
🔧 (chat_service.py): Refactor conversation deduplication logic and source statistics calculation for better performance and accuracy
🔧 (langflow_history_service.py): Implement session ownership filtering for Google users and enhance session ownership tracking functionality
🔧 (session_ownership_service.py): Create SessionOwnershipService to track session ownership for proper message history separation
