Use hardcover-api service with pagination

Replace the old hardcover sync usage with a new hardcover-api.service implementation that adds types, a reusable extractBooks helper, and paginated GraphQL queries (limit/offset) to fully fetch status and list books. Update API route import to use the new service. Fix ManageShelfModal to initialize rssUrl/listId as empty strings. Update tests to mock the new service and add encryption format helper mocking.

tests/api/hardcover-shelves.routes.test.ts

@@ -35,7 +35,7 @@ vi.mock('@/lib/services/encryption.service', () => ({
   getEncryptionService: () => encryptionMock,
 }));
 
-vi.mock('@/lib/services/hardcover-sync.service', () => ({
+vi.mock('@/lib/services/hardcover-api.service', () => ({
   fetchHardcoverList: fetchHardcoverListMock,
 }));