Add authors pages and requestType notifications

Introduce full authors browsing/detail feature and enhance notifications to support type-specific titles.

- Add server APIs: authors search, author detail, and author books routes (audnexus integration) that require auth and enrich results with library matches.
- Add frontend pages/components: /authors listing and /authors/[asin] detail pages; AuthorCard, AuthorGrid, AuthorDetailCard, SimilarAuthorsRow, and related skeletons.
- Add hook and integration stubs: new useAuthors hook and audnexus-authors integration; update audible service to expose audibleBaseUrl.
- Update AudiobookDetailsModal to use audibleBaseUrl and link author names to author detail pages.
- Add header navigation link to Authors.
- Notifications: extend docs and code to include requestType (audiobook|ebook), add getEventTitle/getEventMeta helpers, update queue signature and providers/processors/tests to pass/handle requestType so titles can be resolved per request type.
- Misc: job queue, processors, provider tests and notification tests updated to reflect new behavior.

This change enables browsing authors and provides type-aware notification titles without per-provider changes.

src/lib/hooks/useAudiobooks.ts

@@ -12,6 +12,7 @@ export interface Audiobook {
   asin: string;
   title: string;
   author: string;
+  authorAsin?: string;
   narrator?: string;
   description?: string;
   coverArtUrl?: string;
@@ -81,6 +82,7 @@ export function useAudiobookDetails(asin: string | null) {
 
   return {
     audiobook: data?.audiobook || null,
+    audibleBaseUrl: data?.audibleBaseUrl || 'https://www.audible.com',
     isLoading,
     error,
   };

src/lib/hooks/useAuthors.ts

@@ -0,0 +1,88 @@
+/**
+ * Component: Authors Fetching Hooks
+ * Documentation: documentation/frontend/components.md
+ */
+
+'use client';
+
+import useSWR from 'swr';
+import { authenticatedFetcher } from '@/lib/utils/api';
+import { Audiobook } from './useAudiobooks';
+
+export interface Author {
+  asin: string;
+  name: string;
+  description?: string;
+  image?: string;
+  genres: string[];
+  similarCount: number;
+}
+
+export interface SimilarAuthor {
+  asin: string;
+  name: string;
+  image?: string;
+}
+
+export interface AuthorDetail {
+  asin: string;
+  name: string;
+  description?: string;
+  image?: string;
+  genres: string[];
+  similar: SimilarAuthor[];
+  audibleUrl?: string;
+}
+
+export function useAuthorSearch(name: string) {
+  const shouldFetch = name && name.length > 0;
+  const endpoint = shouldFetch
+    ? `/api/authors/search?name=${encodeURIComponent(name)}`
+    : null;
+
+  const { data, error, isLoading } = useSWR(endpoint, authenticatedFetcher, {
+    revalidateOnFocus: false,
+    dedupingInterval: 30000,
+  });
+
+  return {
+    authors: (data?.authors || []) as Author[],
+    query: data?.query || '',
+    isLoading: shouldFetch && isLoading,
+    error,
+  };
+}
+
+export function useAuthorDetail(asin: string | null) {
+  const endpoint = asin ? `/api/authors/${asin}` : null;
+
+  const { data, error, isLoading } = useSWR(endpoint, authenticatedFetcher, {
+    revalidateOnFocus: false,
+    dedupingInterval: 300000, // Cache for 5 minutes
+  });
+
+  return {
+    author: (data?.author || null) as AuthorDetail | null,
+    isLoading,
+    error,
+  };
+}
+
+export function useAuthorBooks(asin: string | null, authorName: string | null) {
+  const shouldFetch = asin && authorName;
+  const endpoint = shouldFetch
+    ? `/api/authors/${asin}/books?name=${encodeURIComponent(authorName)}`
+    : null;
+
+  const { data, error, isLoading } = useSWR(endpoint, authenticatedFetcher, {
+    revalidateOnFocus: false,
+    dedupingInterval: 60000, // Cache for 1 minute
+  });
+
+  return {
+    books: (data?.books || []) as Audiobook[],
+    totalBooks: data?.totalBooks || 0,
+    isLoading: !!shouldFetch && isLoading,
+    error,
+  };
+}