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/components/HistoryRow.test.ts

@@ -2,7 +2,7 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/svelte';
 import HistoryRow from './HistoryRow.svelte';
 import type { HistoryEvent } from '$lib/api/history';
-import type { TrackRef } from '$lib/api/types';
+import { makeTrack } from '$test-utils/fixtures/track';
 
 const playQueue = vi.fn();
 
@@ -10,16 +10,11 @@ vi.mock('$lib/player/store.svelte', () => ({
   playQueue: (...args: unknown[]) => playQueue(...args)
 }));
 
-const sampleTrack: TrackRef = {
-  id: 'track-1',
+const sampleTrack = makeTrack({
   title: 'Song Title',
-  album_id: 'album-1',
   album_title: 'Album',
-  artist_id: 'artist-1',
-  artist_name: 'Artist Name',
-  duration_sec: 200,
-  stream_url: '/stream/track-1'
-};
+  artist_name: 'Artist Name'
+});
 
 const sampleEvent: HistoryEvent = {
   id: 'event-1',