- Add react-easy-crop for circular crop + zoom UI on avatar upload
- Create server-side getUserAvatarUrl utility for generating pre-signed URLs
- Update all nav components (admin, jury, mentor, observer) to show user avatars
- Add avatar URLs to user list, mentor list, and project detail API responses
- Replace initials-only avatars with UserAvatar component across admin pages
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
