Add branding system with customizable launch screen and app icon
- Add AppIconView with configurable title, subtitle, icon, and colors
- Add LaunchScreenView with multiple pattern styles (dots, grid, radial, none)
- Add layout styles (iconAboveTitle, titleAboveIcon, iconOnly, titleOnly)
- Add IconGeneratorView for exporting 1024px app icons
- Add BrandingPreviewView for previewing branding assets
- Add AppLaunchView wrapper for animated app launch
- Add comprehensive BRANDING_GUIDE.md documentation
- Remove all casino-specific references, make fully generic