fix(synology): correct multi-album passphrase assignment and stale trek_photos

- ProviderPicker now tracks per-asset album passphrase in a Map; on confirm,
  assets are grouped by passphrase and submitted as separate batches so each
  asset receives its own album's passphrase instead of the last-selected one
- getOrCreateTrekPhoto unconditionally overwrites the stored passphrase when
  a fresh one is supplied, allowing re-adds to heal a stuck bad passphrase
- deleteTrekPhotoIfOrphan purges the trek_photos row for provider assets when
  no trip_photos or journey_photos reference it anymore; wired into
  removeTripPhoto, removeAlbumLink, and deletePhoto so remove + re-add is a
  clean slate
- Three new integration tests: SYNO-090 (passphrase overwrite), SYNO-091
  (orphan cleanup), SYNO-092 (remove + re-add restores correct passphrase)

server/src/services/journeyService.ts

@@ -1,7 +1,7 @@
 import { db } from '../db/database';
 import { broadcastToUser } from '../websocket';
 import type { Journey, JourneyEntry, JourneyPhoto, JourneyContributor } from '../types';
-import { getOrCreateTrekPhoto, getOrCreateLocalTrekPhoto, setTrekPhotoProvider } from './memories/photoResolverService';
+import { getOrCreateTrekPhoto, getOrCreateLocalTrekPhoto, setTrekPhotoProvider, deleteTrekPhotoIfOrphan } from './memories/photoResolverService';
 
 function ts(): number {
   return Date.now();
@@ -718,6 +718,7 @@ export function deletePhoto(photoId: number, userId: number): (JourneyPhoto & {
   if (!canEdit(photo.journey_id, userId)) return null;
 
   db.prepare('DELETE FROM journey_photos WHERE id = ?').run(photoId);
+  deleteTrekPhotoIfOrphan(photo.photo_id);
 
   // clean up empty Gallery entries left behind
   const remaining = db.prepare('SELECT 1 FROM journey_photos WHERE entry_id = ?').get(photo.entry_id);