- Remove standalone InboxService and move functionality to UserService
- Rename inbox to user notifications for better API consistency
- Add ListUserNotifications, UpdateUserNotification, DeleteUserNotification methods
- Update frontend components to use new notification endpoints
- Update store layer to support new notification model
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>