- Remove GroupBounty/PersonalBounty subclasses, use Bounty with optional created_by_user_id
- Combine UserData/GroupData into RoomData with room_id and is_group fields
- Add group_id field to TrackingData (supports negative Telegram group IDs)
- Add test_bounty_comparison_not_equal for verifying different bounties are not equal
- Update core/__init__.py exports