- enhance webcam filter web app with new features and UI improvements

- add responsive design with mobile optimization
- implement camera device selection and quality settings
- add photo snapshot and video recording capabilities
- create filter intensity control slider
- implement filter presets (vintage, vaporwave, noir, etc.)
- add keyboard shortcuts for navigation and control
- implement PWA support with manifest and service worker
- improve filter rendering with intensity parameter
- add loading and error states for better UX
- implement fullscreen mode and settings panel

Author: TobiasMue91