test(web): PlaylistCard cover-img assertion uses DOM query

The <img alt=""> production element renders as role="presentation"
(decorative — playlist name is in sibling text). screen.getByRole('img')
doesn't match presentation-role elements. Switch to
container.querySelector('img') so the test doesn't fight the
correct a11y choice. Production code unchanged.

web/src/lib/components/PlaylistCard.test.ts

@@ -32,9 +32,15 @@ describe('PlaylistCard', () => {
   });
 
   test('renders cover image when cover_url is set', () => {
-    render(PlaylistCard, { props: { playlist: { ...base, cover_url: '/api/playlists/p-1/cover' } } });
-    const img = screen.getByRole('img');
-    expect(img.getAttribute('src')).toBe('/api/playlists/p-1/cover');
+    // The <img> has alt="" (decorative — the playlist name is in the
+    // sibling text below, so duplicating it for screen readers would be
+    // noise). Empty alt makes Testing Library expose role="presentation"
+    // instead of role="img"; query the DOM directly so the assertion
+    // doesn't fight the (correct) a11y choice.
+    const { container } = render(PlaylistCard, { props: { playlist: { ...base, cover_url: '/api/playlists/p-1/cover' } } });
+    const img = container.querySelector('img');
+    expect(img).not.toBeNull();
+    expect(img!.getAttribute('src')).toBe('/api/playlists/p-1/cover');
   });
 
   test('renders glyph fallback when cover_url is empty', () => {