fix(artists): per-artist links on song rails and shared OpenSubsonic refs (#1023)

* fix(artists): per-artist links on song rails and shared OpenSubsonic refs

Song cards in Random Picks and Discover Songs showed joined artist
credits but navigated to a single artistId. Route track surfaces through
resolveTrackArtistRefs and coerce single-object Subsonic JSON payloads.

* docs(changelog): note song-rail multi-artist link fix (PR #1023)

src/components/SongCard.test.tsx

@@ -0,0 +1,43 @@
+import { describe, expect, it, vi } from 'vitest';
+import { screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { renderWithProviders } from '../test/helpers/renderWithProviders';
+import SongCard from './SongCard';
+import type { SubsonicSong } from '../api/subsonicTypes';
+
+const navigateToArtist = vi.fn();
+
+vi.mock('../hooks/useNavigateToArtist', () => ({
+  useNavigateToArtist: () => navigateToArtist,
+}));
+
+vi.mock('../cover/useLibraryCoverRef', () => ({
+  useTrackCoverRef: () => undefined,
+}));
+
+function song(overrides: Partial<SubsonicSong>): SubsonicSong {
+  return {
+    id: 's1', title: 'Track', artist: 'A', album: 'Alb', albumId: 'al1', duration: 100,
+    ...overrides,
+  } as SubsonicSong;
+}
+
+describe('SongCard', () => {
+  it('splits OpenSubsonic artists into individual links', async () => {
+    navigateToArtist.mockClear();
+    const user = userEvent.setup();
+    renderWithProviders(
+      <SongCard
+        disableArtwork
+        song={song({
+          artist: 'Apocalyptica', artistId: 'a1',
+          artists: [{ id: 'a1', name: 'Apocalyptica' }, { id: 'a2', name: 'Joe Duplantier' }],
+        })}
+      />,
+    );
+    expect(screen.getByText('Apocalyptica')).toHaveClass('track-artist-link');
+    expect(screen.getByText('Joe Duplantier')).toHaveClass('track-artist-link');
+    await user.click(screen.getByText('Joe Duplantier'));
+    expect(navigateToArtist).toHaveBeenCalledWith('a2');
+  });
+});