refactor(web): sweep 24 test files to use makeTrack/makeTracks fixtures (#375)

Replaces inline TrackRef literal redefinitions with calls to the
test-utils helper. Tests that asserted on default field values
(e.g. track titles, artist names rendered in the DOM) keep explicit
overrides; tests that only need a stub for shape now use makeTrack()
with no overrides.

PlaylistCard.test.ts, PlaylistTrackRow.test.ts, and playlist.test.ts
SKIPPED — they use PlaylistTrack (with track_id/added_at), not TrackRef.
ArtistCard.svelte and +page.svelte route files (matched by initial grep)
SKIPPED — live code, not test files.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/routes/albums/[id]/album.test.ts

@@ -4,6 +4,7 @@ import { flushSync } from 'svelte';
 import { mockQuery } from '../../../test-utils/query';
 import { emptyLikesMock } from '../../../test-utils/mocks/likes';
 import type { AlbumDetail, TrackRef } from '$lib/api/types';
+import { makeTrack } from '$test-utils/fixtures/track';
 
 const state = vi.hoisted(() => ({ pageParams: { id: 'xyz' } as Record<string, string> }));
 
@@ -25,14 +26,14 @@ import AlbumPage from './+page.svelte';
 import { createAlbumQuery } from '$lib/api/queries';
 
 function track(id: string, title: string, number: number, dur: number): TrackRef {
-  return {
+  return makeTrack({
     id, title,
     album_id: 'xyz', album_title: 'Kind of Blue',
     artist_id: 'md', artist_name: 'Miles Davis',
-    track_number: number, disc_number: 1,
+    track_number: number,
     duration_sec: dur,
     stream_url: `/api/tracks/${id}/stream`
-  };
+  });
 }
 
 afterEach(() => {