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/lib/player/store.test.ts

@@ -19,6 +19,7 @@ import {
 } from './store.svelte';
 import type { TrackRef } from '$lib/api/types';
 import { writePersistedQueue, clearPersistedQueue } from './persisted';
+import { makeTrack } from '$test-utils/fixtures/track';
 
 vi.mock('$lib/auth/store.svelte', () => ({
   user: {
@@ -29,14 +30,12 @@ vi.mock('$lib/auth/store.svelte', () => ({
 }));
 
 function track(id: string, dur = 180): TrackRef {
-  return {
-    id, title: `T ${id}`,
-    album_id: 'a1', album_title: 'A',
-    artist_id: 'ar1', artist_name: 'Ar',
-    track_number: Number(id), disc_number: 1,
+  return makeTrack({
+    id,
+    title: `T ${id}`,
     duration_sec: dur,
     stream_url: `/api/tracks/${id}/stream`
-  };
+  });
 }
 
 beforeEach(() => {