feat: Immich album linking with auto-sync (#206)

- Link Immich albums to trips — photos sync automatically
- Album picker shows all user's Immich albums
- Linked albums displayed as chips with sync/unlink buttons
- Auto-sync on link: fetches all album photos and adds to trip
- Manual re-sync button for each linked album
- DB migration: trip_album_links table

fix: shared Immich photos visible to other trip members

- Thumbnail/original proxy now uses photo owner's Immich credentials
  when userId query param is provided, fixing 404 for shared photos
- i18n: album keys for all 12 languages

client/src/i18n/translations/nl.ts

@@ -1346,6 +1346,12 @@ const nl: Record<string, string> = {
   'memories.newest': 'Nieuwste eerst',
   'memories.allLocations': 'Alle locaties',
   'memories.addPhotos': 'Foto\'s toevoegen',
+  'memories.linkAlbum': 'Album koppelen',
+  'memories.selectAlbum': 'Immich-album selecteren',
+  'memories.noAlbums': 'Geen albums gevonden',
+  'memories.syncAlbum': 'Album synchroniseren',
+  'memories.unlinkAlbum': 'Ontkoppelen',
+  'memories.photos': 'fotos',
   'memories.selectPhotos': 'Selecteer foto\'s uit Immich',
   'memories.selectHint': 'Tik op foto\'s om ze te selecteren.',
   'memories.selected': 'geselecteerd',