Support language/format/publisher for Audible

Expose language, formatType, and publisherName from the Audible catalog. Update audible.service to map format_type and publisher_name (and language) into the AudibleAudiobook model, update AudiobookDetailsModal to display language and format using the CSS "capitalize" class, and update documentation to list the new fields. Add unit tests to verify the mappings, details propagation, and behavior when fields are omitted.

tests/integrations/audible.service.test.ts

@@ -49,6 +49,8 @@ interface ProductOverrides {
   runtime_length_min?: number;
   release_date?: string;
   language?: string;
+  format_type?: string;
+  publisher_name?: string;
   rating?: { overall_distribution?: { display_stars?: number } };
   category_ladders?: Array<{ ladder: Array<{ name: string }> }>;
   series?: Array<{ asin?: string; title?: string; sequence?: string }>;
@@ -615,6 +617,47 @@ describe('AudibleService', () => {
       const genreSet = new Set(results[0].genres);
       expect(genreSet.size).toBe(5);
     });
+
+    it('maps language from catalog product', async () => {
+      const products = [makeProduct({ language: 'english' })];
+      apiClientMock.get.mockResolvedValue(apiResponse(makeProductsResponse(products)));
+
+      const service = new AudibleService();
+      const { results } = await service.search('test', 1);
+
+      expect(results[0].language).toBe('english');
+    });
+
+    it('maps format_type to formatType from catalog product', async () => {
+      const products = [makeProduct({ format_type: 'unabridged' })];
+      apiClientMock.get.mockResolvedValue(apiResponse(makeProductsResponse(products)));
+
+      const service = new AudibleService();
+      const { results } = await service.search('test', 1);
+
+      expect(results[0].formatType).toBe('unabridged');
+    });
+
+    it('maps publisher_name to publisherName from catalog product', async () => {
+      const products = [makeProduct({ publisher_name: 'Penguin Random House Audio' })];
+      apiClientMock.get.mockResolvedValue(apiResponse(makeProductsResponse(products)));
+
+      const service = new AudibleService();
+      const { results } = await service.search('test', 1);
+
+      expect(results[0].publisherName).toBe('Penguin Random House Audio');
+    });
+
+    it('leaves formatType and publisherName undefined when catalog product omits them', async () => {
+      const products = [makeProduct()];
+      apiClientMock.get.mockResolvedValue(apiResponse(makeProductsResponse(products)));
+
+      const service = new AudibleService();
+      const { results } = await service.search('test', 1);
+
+      expect(results[0].formatType).toBeUndefined();
+      expect(results[0].publisherName).toBeUndefined();
+    });
   });
 
   // -------------------------------------------------------------------------
@@ -1262,6 +1305,9 @@ describe('AudibleService', () => {
           runtimeLengthMin: '300',
           genres: ['Fiction'],
           rating: '4.7',
+          language: 'english',
+          formatType: 'unabridged',
+          publisherName: 'Test Publisher',
         },
       });
 
@@ -1271,6 +1317,9 @@ describe('AudibleService', () => {
       expect(details?.title).toBe('Audnexus Book');
       expect(details?.author).toBe('Author A');
       expect(details?.durationMinutes).toBe(300);
+      expect(details?.language).toBe('english');
+      expect(details?.formatType).toBe('unabridged');
+      expect(details?.publisherName).toBe('Test Publisher');
       // Catalog API should NOT be called when Audnexus succeeds.
       expect(apiClientMock.get).not.toHaveBeenCalled();
     });