fix(web/test): update playlist API tests for api.* call surface (#375)

After e8eff1b migrated playlists.ts from raw apiFetch to the api.*
wrapper, three test files mocked the wrong surface:

- playlists.test.ts: GET case asserted init.method === 'GET' but
  api.get omits init.method entirely (fetch defaults to GET). Fall
  back to 'GET' when init.method is undefined.
- playlists.refresh-discover.test.ts: re-mock ./client to expose
  `api: { post: vi.fn() }` instead of `apiFetch`; assertions check
  api.post call args.
- playlists.refresh-foryou.test.ts: same.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/src/lib/api/playlists.refresh-discover.test.ts

@@ -2,28 +2,25 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { refreshDiscover } from './playlists';
 
 vi.mock('./client', () => ({
-  apiFetch: vi.fn()
+  api: { post: vi.fn() }
 }));
 
-import { apiFetch } from './client';
+import { api } from './client';
 
 describe('refreshDiscover', () => {
   beforeEach(() => vi.clearAllMocks());
 
   it('POSTs the correct path and returns the response', async () => {
     const sample = { playlist_id: 'abc-123', track_count: 100 };
-    (apiFetch as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
+    (api.post as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
     const got = await refreshDiscover();
-    expect(apiFetch).toHaveBeenCalledWith(
-      '/api/playlists/system/discover/refresh',
-      expect.objectContaining({ method: 'POST' })
-    );
+    expect(api.post).toHaveBeenCalledWith('/api/playlists/system/discover/refresh', {});
     expect(got).toEqual(sample);
   });
 
   it('handles empty-library response', async () => {
     const sample = { playlist_id: null, track_count: 0 };
-    (apiFetch as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
+    (api.post as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
     const got = await refreshDiscover();
     expect(got.playlist_id).toBe(null);
     expect(got.track_count).toBe(0);

web/src/lib/api/playlists.refresh-foryou.test.ts

@@ -2,28 +2,25 @@ import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { refreshForYou } from './playlists';
 
 vi.mock('./client', () => ({
-  apiFetch: vi.fn()
+  api: { post: vi.fn() }
 }));
 
-import { apiFetch } from './client';
+import { api } from './client';
 
 describe('refreshForYou', () => {
   beforeEach(() => vi.clearAllMocks());
 
   it('POSTs the correct path and returns the response', async () => {
     const sample = { playlist_id: 'pl-abc', track_count: 25, track_ids: ['t1', 't2'] };
-    (apiFetch as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
+    (api.post as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
     const got = await refreshForYou();
-    expect(apiFetch).toHaveBeenCalledWith(
-      '/api/playlists/system/for-you/refresh',
-      expect.objectContaining({ method: 'POST' })
-    );
+    expect(api.post).toHaveBeenCalledWith('/api/playlists/system/for-you/refresh', {});
     expect(got).toEqual(sample);
   });
 
   it('handles empty-library response', async () => {
     const sample = { playlist_id: null, track_count: 0, track_ids: [] };
-    (apiFetch as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
+    (api.post as unknown as ReturnType<typeof vi.fn>).mockResolvedValueOnce(sample);
     const got = await refreshForYou();
     expect(got.playlist_id).toBe(null);
     expect(got.track_ids).toEqual([]);

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

@@ -29,7 +29,8 @@ describe('playlists API helper', () => {
     expect(r.public).toEqual([]);
     const call = spy.mock.calls[0];
     expect(call[0]).toBe('/api/playlists?kind=user');
-    expect((call[1] as RequestInit).method).toBe('GET');
+    // GET is fetch's default method; api.get omits init.method entirely.
+    expect((call[1] as RequestInit | undefined)?.method ?? 'GET').toBe('GET');
   });
 
   test('listPlaylists passes kind=system through the query string', async () => {