fix(synology): paginate all three album sources past 100 albums and tighten targetUserId type

- Extract _fetchAllSynologyAlbums helper that loops until the source is
  exhausted; listSynologyAlbums now uses it for personal, shared-out,
  and shared-with-me instead of a hard-capped single request of 100
- Make getSynologyAssetInfo targetUserId required (number, not number|undefined)
  to match every call site and eliminate an implicit any at the _requestSynologyApi
  boundary

server/src/types.ts

@@ -350,6 +350,7 @@ export interface TrekPhoto {
   thumbnail_path?: string | null;
   width?: number | null;
   height?: number | null;
+  passphrase?: string | null;
   created_at: string;
 }