feat(web): add home/albums/artists API clients for M6a

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/lib/api/albums.test.ts

@@ -0,0 +1,33 @@
+import { afterEach, describe, expect, test, vi } from 'vitest';
+
+vi.mock('./client', () => ({
+  api: { get: vi.fn() }
+}));
+
+import { listAlbumsAlpha } from './albums';
+import { qk } from './queries';
+import { api } from './client';
+
+afterEach(() => vi.clearAllMocks());
+
+describe('albums client', () => {
+  test('listAlbumsAlpha hits /api/library/albums with paging', async () => {
+    (api.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      items: [], total: 0, limit: 50, offset: 0
+    });
+    await listAlbumsAlpha(50, 0);
+    expect(api.get).toHaveBeenCalledWith('/api/library/albums?limit=50&offset=0');
+  });
+
+  test('listAlbumsAlpha honors custom limit and offset', async () => {
+    (api.get as ReturnType<typeof vi.fn>).mockResolvedValueOnce({
+      items: [], total: 0, limit: 25, offset: 100
+    });
+    await listAlbumsAlpha(25, 100);
+    expect(api.get).toHaveBeenCalledWith('/api/library/albums?limit=25&offset=100');
+  });
+
+  test('qk.albumsAlpha key is stable', () => {
+    expect(qk.albumsAlpha()).toEqual(['albumsAlpha']);
+  });
+});