- Add migration script to convert and copy images
- Include 7 events (Karaoke, Pub Quiz, etc.) in WebP format
- Include 9 gallery images in WebP format
- Update .gitignore to allow images in data/images/
- Add migration documentation in MIGRATION_README.md
Images are stored in backend/data/images/ which maps to
the persistent Fly.io volume at /app/data/
