- Add Flutter mobile app in mobileapp/ directory
- Implement dual authentication: manual login + QR code scanning
- Add /mobileapp endpoint for secure QR code token generation
- UUID-based one-time tokens with 5-minute expiration
- Complete VidAI API integration (jobs, analysis, notifications)
- Add 'Link Mobile App' button to API tokens page
- QR code generation using JavaScript QRCode library
- Secure token storage with Flutter Secure Storage
- Cross-platform support (Android + iOS)
- Modern Material Design 3 UI with professional styling

Security features:
- One-time use UUIDs for QR code authentication
- 5-minute expiration windows
- Host validation and secure token generation
- Enterprise-grade mobile app security

Files added/modified:
- mobileapp/ (complete Flutter app)
- templates/mobileapp_link.html (QR code display page)
- templates/api_tokens.html (added Link Mobile App button)
- vidai/web.py (added /mobileapp endpoint)
- vidai/api.py (added /api/create_token JSON endpoint)