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/app/series/[asin]/page.tsx

@@ -0,0 +1,117 @@
+/**
+ * Component: Series Detail Page
+ * Documentation: documentation/frontend/components.md
+ */
+
+'use client';
+
+import { use, useCallback } from 'react';
+import { useRouter, useSearchParams } from 'next/navigation';
+import { Header } from '@/components/layout/Header';
+import { AudiobookGrid } from '@/components/audiobooks/AudiobookGrid';
+import { SeriesDetailCard, SeriesDetailSkeleton } from '@/components/series/SeriesDetailCard';
+import { SimilarSeriesRow, SimilarSeriesSkeleton } from '@/components/series/SimilarSeriesRow';
+import { useSeriesDetail } from '@/lib/hooks/useSeries';
+import { ProtectedRoute } from '@/components/auth/ProtectedRoute';
+import { CardSizeControls } from '@/components/ui/CardSizeControls';
+import { SquareCoversToggle } from '@/components/ui/SquareCoversToggle';
+import { usePreferences } from '@/contexts/PreferencesContext';
+
+export default function SeriesDetailPage({
+  params,
+}: {
+  params: Promise<{ asin: string }>;
+}) {
+  const { asin } = use(params);
+  const router = useRouter();
+  const searchParams = useSearchParams();
+  const fromSeriesTitle = searchParams.get('from');
+  const { series, isLoading: seriesLoading } = useSeriesDetail(asin);
+  const { cardSize, setCardSize, squareCovers, setSquareCovers } = usePreferences();
+
+  const handleBack = useCallback(() => {
+    // Use browser back if we came from within the app, otherwise fallback to /series
+    if (window.history.length > 1) {
+      router.back();
+    } else {
+      router.push('/series');
+    }
+  }, [router]);
+
+  return (
+    <ProtectedRoute>
+      <div className="min-h-screen">
+        <Header />
+
+        <main className="container mx-auto px-4 py-6 sm:py-8 max-w-7xl space-y-8">
+          {/* Back navigation */}
+          <button
+            onClick={handleBack}
+            className="inline-flex items-center gap-1.5 text-sm text-gray-500 dark:text-gray-400 hover:text-indigo-600 dark:hover:text-indigo-400 transition-colors"
+          >
+            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 19l-7-7 7-7" />
+            </svg>
+            {fromSeriesTitle ? `Back to ${fromSeriesTitle}` : 'Back to Series'}
+          </button>
+
+          {/* Series Detail Card */}
+          {seriesLoading ? (
+            <SeriesDetailSkeleton squareCovers={squareCovers} />
+          ) : series ? (
+            <SeriesDetailCard series={series} squareCovers={squareCovers} />
+          ) : (
+            <div className="text-center py-16 space-y-4">
+              <svg className="mx-auto h-16 w-16 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4.5c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z" />
+              </svg>
+              <p className="text-xl text-gray-600 dark:text-gray-400">Series not found</p>
+            </div>
+          )}
+
+          {/* Similar Series */}
+          {seriesLoading ? (
+            <SimilarSeriesSkeleton squareCovers={squareCovers} />
+          ) : series && series.similarSeries.length > 0 ? (
+            <SimilarSeriesRow series={series.similarSeries} currentSeriesTitle={series.title} squareCovers={squareCovers} />
+          ) : null}
+
+          {/* Books Section */}
+          {series && (
+            <div className="space-y-6">
+              {/* Sticky Books Header */}
+              <div className="sticky top-14 sm:top-16 z-30">
+                <div className="bg-white/90 dark:bg-gray-800/90 backdrop-blur-md rounded-2xl px-4 sm:px-6 py-3 border border-gray-200/50 dark:border-gray-700/50 shadow-sm">
+                  <div className="flex items-center gap-3">
+                    <div className="w-1 h-6 bg-gradient-to-b from-blue-500 to-purple-500 rounded-full" />
+                    <h2 className="text-xl sm:text-2xl font-bold text-gray-900 dark:text-gray-100 truncate">
+                      Books in Series
+                    </h2>
+                    {series.books.length > 0 && (
+                      <span className="text-sm text-gray-600 dark:text-gray-400 hidden sm:inline whitespace-nowrap">
+                        ({series.books.length} title{series.books.length !== 1 ? 's' : ''})
+                      </span>
+                    )}
+                    <div className="ml-auto flex items-center gap-1">
+                      <SquareCoversToggle enabled={squareCovers} onToggle={setSquareCovers} />
+                      <CardSizeControls size={cardSize} onSizeChange={setCardSize} />
+                    </div>
+                  </div>
+                </div>
+              </div>
+
+              {/* Books Grid */}
+              <AudiobookGrid
+                audiobooks={series.books}
+                isLoading={seriesLoading}
+                emptyMessage={`No books found for ${series.title}`}
+                cardSize={cardSize}
+                squareCovers={squareCovers}
+              />
+            </div>
+          )}
+        </main>
+      </div>
+    </ProtectedRoute>
+  );
+}