Add series browsing, search, and detail UI

Introduce full support for Audible series exploration: API routes, frontend pages, components, hooks, and integrations. Key changes:

- Prisma: add Audiobook.seriesAsin for linking audiobooks to series detail pages.
- Backend: add /api/series/search and /api/series/[asin] routes that require auth; scrape Audible series data and enrich books with library availability.
- Integrations/services: add audible-series integration and update request/HTTP services to support the workflow.
- Frontend: add /series and /series/[asin] pages, new components (SeriesCard, SeriesGrid, SeriesDetailCard, SimilarSeriesRow) and wire them to a new useSeries hook; update AudiobookDetailsModal to show/link series; add Series link to Header.
- Misc: extend audiobook types with series fields and add seriesLabels to language-config for scraping.

These changes enable users to search for series, view series metadata and books, and navigate between audiobook and series detail pages.

src/lib/hooks/useAudiobooks.ts

@@ -20,6 +20,9 @@ export interface Audiobook {
   releaseDate?: string;
   rating?: number;
   genres?: string[];
+  series?: string;         // Series name (e.g., "A Song of Ice and Fire")
+  seriesPart?: string;     // Position in series (e.g., "1", "1.5")
+  seriesAsin?: string;     // Audible ASIN for the series (links to /series/{asin})
   isAvailable?: boolean;  // Set by real-time matching against plex_library
   plexGuid?: string | null;
   dbId?: string | null;

src/lib/hooks/useSeries.ts

@@ -0,0 +1,75 @@
+/**
+ * Component: Series 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 SeriesSummary {
+  asin: string;
+  title: string;
+  bookCount: number;
+  rating?: number;
+  ratingCount?: number;
+  tags: string[];
+  coverArtUrl?: string;
+  audibleUrl: string;
+}
+
+export interface SimilarSeries {
+  asin: string;
+  title: string;
+  bookCount?: number;
+  coverArtUrl?: string;
+}
+
+export interface SeriesDetail {
+  asin: string;
+  title: string;
+  bookCount: number;
+  rating?: number;
+  ratingCount?: number;
+  description?: string;
+  tags: string[];
+  books: Audiobook[];
+  similarSeries: SimilarSeries[];
+  audibleUrl: string;
+}
+
+export function useSeriesSearch(query: string) {
+  const shouldFetch = query && query.length > 0;
+  const endpoint = shouldFetch
+    ? `/api/series/search?q=${encodeURIComponent(query)}`
+    : null;
+
+  const { data, error, isLoading } = useSWR(endpoint, authenticatedFetcher, {
+    revalidateOnFocus: false,
+    dedupingInterval: 30000,
+  });
+
+  return {
+    series: (data?.series || []) as SeriesSummary[],
+    query: data?.query || '',
+    isLoading: shouldFetch && isLoading,
+    error,
+  };
+}
+
+export function useSeriesDetail(asin: string | null) {
+  const endpoint = asin ? `/api/series/${asin}` : null;
+
+  const { data, error, isLoading } = useSWR(endpoint, authenticatedFetcher, {
+    revalidateOnFocus: false,
+    dedupingInterval: 300000, // Cache for 5 minutes
+  });
+
+  return {
+    series: (data?.series || null) as SeriesDetail | null,
+    isLoading,
+    error,
+  };
+}