fix(cover): restore audiobookcovers searches

Use separate title and author parameters to match the current upstream search form and restore cover results. Add regression coverage for title-only searches, whitespace trimming, and query encoding.

server/src/modules/cover/providers/audiobookcovers-cover-provider.test.ts

@@ -69,7 +69,35 @@ describe('AudiobookCoversCoverProvider', () => {
     const [requestUrl] = fetchMock.mock.calls[0] as [string];
     const parsed = new URL(requestUrl);
     expect(parsed.pathname).toBe('/search');
-    expect(parsed.searchParams.get('q')).toBe('Dune Frank Herbert');
+    expect(parsed.searchParams.get('title')).toBe('Dune');
+    expect(parsed.searchParams.get('author')).toBe('Frank Herbert');
+    expect(parsed.searchParams.has('q')).toBe(false);
+  });
+
+  it.each([undefined, '   '])('searches by title when author is %j', async (author) => {
+    fetchMock.mockResolvedValueOnce(new Response(pageHtml(['1c98a3d5-9c05-4157-81a5-558cbb5ea87a']), { status: 200 }));
+
+    const results = await provider.search({ title: 'Dune', author, isAudiobook: true });
+
+    expect(results).toHaveLength(1);
+    const [requestUrl] = fetchMock.mock.calls[0] as [string];
+    const parsed = new URL(requestUrl);
+    expect(parsed.searchParams.get('title')).toBe('Dune');
+    expect(parsed.searchParams.has('author')).toBe(false);
+    expect(parsed.searchParams.has('q')).toBe(false);
+  });
+
+  it('trims and encodes title and author as separate search parameters', async () => {
+    fetchMock.mockResolvedValueOnce(new Response(pageHtml([]), { status: 200 }));
+
+    await provider.search({ title: '  Sense & Sensibility  ', author: '  Jane Austen  ', isAudiobook: true });
+
+    const [requestUrl] = fetchMock.mock.calls[0] as [string];
+    const parsed = new URL(requestUrl);
+    expect([...parsed.searchParams.entries()]).toEqual([
+      ['title', 'Sense & Sensibility'],
+      ['author', 'Jane Austen'],
+    ]);
   });
 
   it('deduplicates repeated ids in the response', async () => {

server/src/modules/cover/providers/audiobookcovers-cover-provider.ts

@@ -21,11 +21,14 @@ export class AudiobookCoversCoverProvider implements CoverProvider {
   async search(params: CoverSearchParams): Promise<CoverSearchResult[]> {
     if (!params.isAudiobook) return [];
 
-    const query = this.buildQuery(params);
+    const title = params.title?.trim() ?? '';
+    const author = params.author?.trim() ?? '';
+    const query = author ? `${title} ${author}`.trim() : title;
     if (!query) return [];
 
     const url = new URL(AudiobookCoversCoverProvider.SEARCH_URL);
-    url.searchParams.set('q', query);
+    url.searchParams.set('title', title);
+    if (author) url.searchParams.set('author', author);
 
     try {
       const response = await fetch(url.toString(), {
@@ -69,10 +72,4 @@ export class AudiobookCoversCoverProvider implements CoverProvider {
 
     return results;
   }
-
-  private buildQuery(params: CoverSearchParams): string {
-    const title = params.title?.trim() ?? '';
-    const author = params.author?.trim() ?? '';
-    return author ? `${title} ${author}`.trim() : title;
-  }
 }