Comprehensive iPhone PWA mobile optimization

- Added responsive design for iPhone screen sizes (including iPhone 15 Pro Max)
- Implemented proper touch targets (44px minimum) and mobile interactions
- Added mobile menu button with sidebar toggle functionality
- Enhanced PWA manifest with iPhone-specific configurations
- Added safe area support for notched iPhones (env() CSS functions)
- Improved touch feedback and scroll performance on iOS
- Added mobile-first CSS with proper breakpoints
- Optimized header layout for mobile with better spacing
- Added orientation change handling and mobile-specific animations
- Improved accessibility with proper ARIA labels and touch actions