feat(album): single cover on album detail, track-number rows

Album detail header falls back to a track's cover when the album
record itself has none, and each track row hides its per-track art in
favour of a large album-position number, since the header already
shows the album's cover once.

src/features/album-detail/AlbumDetailPage.tsx

@@ -9,16 +9,17 @@ import { TrackRow } from '../../components/track/TrackRow';
 import { LoadingSkeleton } from '../../components/common/LoadingSkeleton';
 import { ErrorState } from '../../components/common/ErrorState';
 import { EmptyState } from '../../components/common/EmptyState';
-import { useAppDispatch } from '../../hooks/useAppDispatch';
+import { useAppDispatch, useAppSelector } from '../../hooks/useAppDispatch';
 import { setQueue } from '../../store/slices/queue';
 import { formatDuration } from '../../lib/format';
-import { getCoverUrl } from '../../api/endpoints/streaming';
+import { getCoverUrl, getTrackCoverUrl } from '../../api/endpoints/streaming';
 
 export function AlbumDetailPage() {
   const { t } = useTranslation();
   const { albumId } = useParams<{ albumId: string }>();
   const navigate = useNavigate();
   const dispatch = useAppDispatch();
+  const token = useAppSelector((s) => s.auth.accessToken);
 
   const albumQuery = useGetAlbumQuery(albumId ?? '', { skip: !albumId });
   const tracksQuery = useGetAlbumTracksQuery(albumId ?? '', { skip: !albumId });
@@ -42,7 +43,13 @@ export function AlbumDetailPage() {
 
   const album = albumQuery.data;
   const tracks = tracksQuery.data ?? [];
-  const artUrl = getCoverUrl(album?.artUrl);
+  // The album record itself carries no cover; fall back to a track's cover.
+  const coverTrack = tracks.find((t) => t.hasCover);
+  const artUrl =
+    getCoverUrl(album?.artUrl) ??
+    (token && coverTrack
+      ? getTrackCoverUrl(coverTrack.id, token, true)
+      : undefined);
 
   const handlePlayAll = () => {
     if (!tracks.length || !album) return;
@@ -178,7 +185,7 @@ export function AlbumDetailPage() {
             />
           )}
         {tracks.map((track, i) => (
-          <TrackRow key={track.id} track={track} index={i} />
+          <TrackRow key={track.id} track={track} index={i} hideArt />
         ))}
       </ScrollArea>
     </div>