Updated all branding assets to use Naomi's library avatar (with the playful "shh" gesture):
- Navigation icon in header
- Favicon for browser tabs
- All PWA icon sizes (72x72 through 512x512, including maskable icons)
- Hero avatar on home page between title and subtitle
The avatar features consistent styling across all uses:
- Circular display with elegant borders
- Hover animations for interactive elements
- Shadows for visual depth
- Perfectly integrated with the witch-purple theme
All icons generated from the source image at multiple resolutions for optimal display on all devices and contexts.
