a) Admin panel now respects the site's light/dark theme toggle via CSS
custom properties that respond to [data-theme='light'] on <html>.
All hardcoded dark colors replaced with semantic CSS variables.
b) Improved contrast in dark mode: secondary text changed from #666/#555
to #a0a0a0, muted text from #555 to #707070. All text is now clearly
readable against dark backgrounds.
c) Backup system was already implemented in yaml-service.ts (creates
timestamped backups in content/.backups/ before each save, keeps last
10 versions). Now the UI shows a confirmation message that a backup
was created after each successful save.
- Add /admin route with password-protected visual page builder
- Page Builder: manage hero images, standalone albums, subpages, and sections
- Album Picker: browse all shared Immich albums with search and filtering
- Settings Editor: theme, grid, footer, legal, SEO configuration
- YAML service with atomic writes and automatic backups (content/.backups/)
- HMAC-signed admin sessions (24h expiry, HttpOnly cookies)
- API endpoints: /api/admin/{auth,gallery,settings,albums,reload}
- Enable with ADMIN_PASSWORD env var; disabled by default
- invalidateConfigCache() export for hot-reload after saves
