1. Setup redirect flow (setup -> loading -> login):
- Add /loading to exempt paths
- Redirect setup to login after completion
- Redirect loading to login when initialization complete
2. Close pages after completion:
- Block access to /setup after setup is done
- Block access to /loading after initialization complete
- Proper redirect handling prevents re-access
3. Fix WebSocket 403 error:
- Change /ws/progress to /ws/connect (correct endpoint)
- Add /ws/connect to exempt paths
- Subscribe to 'system' room for progress updates
- Fix message data handling format
- Create loading.html template with WebSocket-based progress updates
- Update initialization_service to emit progress events via ProgressService
- Modify setup endpoint to run initialization in background and redirect to loading page
- Add /loading route in page_controller
- Show real-time progress for series sync, NFO scan, and media scan steps
- Display completion message with button to continue to app
- Handle errors with visual feedback
