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/components/authors/AuthorDetailCard.tsx

@@ -0,0 +1,135 @@
+/**
+ * Component: Author Detail Card
+ * Documentation: documentation/frontend/components.md
+ *
+ * Hero section for the author detail page with circular portrait,
+ * name, collapsible biography, and genre pills.
+ */
+
+'use client';
+
+import React, { useState } from 'react';
+import Image from 'next/image';
+import { AuthorDetail } from '@/lib/hooks/useAuthors';
+
+interface AuthorDetailCardProps {
+  author: AuthorDetail;
+}
+
+export function AuthorDetailCard({ author }: AuthorDetailCardProps) {
+  const [expanded, setExpanded] = useState(false);
+  const hasLongDescription = (author.description?.length || 0) > 300;
+
+  return (
+    <div className="flex flex-col sm:flex-row items-center sm:items-start gap-6 sm:gap-8">
+      {/* Circular Portrait */}
+      <div className="flex-shrink-0">
+        <div className="relative w-36 h-36 sm:w-44 sm:h-44 lg:w-52 lg:h-52 rounded-full overflow-hidden shadow-xl shadow-black/20 dark:shadow-black/40">
+          {author.image ? (
+            <Image
+              src={author.image}
+              alt={author.name}
+              fill
+              className="object-cover"
+              sizes="(max-width: 640px) 144px, (max-width: 1024px) 176px, 208px"
+              priority
+            />
+          ) : (
+            <div className="absolute inset-0 bg-gradient-to-br from-blue-100 to-indigo-200 dark:from-blue-900 dark:to-indigo-900 flex items-center justify-center">
+              <svg className="w-1/3 h-1/3 text-blue-400 dark:text-blue-300" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.5} d="M15.75 6a3.75 3.75 0 11-7.5 0 3.75 3.75 0 017.5 0zM4.501 20.118a7.5 7.5 0 0114.998 0A17.933 17.933 0 0112 21.75c-2.676 0-5.216-.584-7.499-1.632z" />
+              </svg>
+            </div>
+          )}
+        </div>
+      </div>
+
+      {/* Author Info */}
+      <div className="flex-1 min-w-0 text-center sm:text-left">
+        <h1 className="text-3xl sm:text-4xl font-bold text-gray-900 dark:text-gray-100">
+          {author.name}
+        </h1>
+
+        {/* Genre Pills */}
+        {author.genres.length > 0 && (
+          <div className="mt-3 flex flex-wrap justify-center sm:justify-start gap-2">
+            {author.genres.map(genre => (
+              <span
+                key={genre}
+                className="inline-block px-3 py-1 text-xs font-medium rounded-full bg-indigo-50 dark:bg-indigo-900/30 text-indigo-600 dark:text-indigo-300"
+              >
+                {genre}
+              </span>
+            ))}
+          </div>
+        )}
+
+        {/* Audible Link */}
+        {author.audibleUrl && (
+          <a
+            href={author.audibleUrl}
+            target="_blank"
+            rel="noopener noreferrer"
+            className="mt-3 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"
+          >
+            View on Audible
+            <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10 6H6a2 2 0 00-2 2v10a2 2 0 002 2h10a2 2 0 002-2v-4M14 4h6m0 0v6m0-6L10 14" />
+            </svg>
+          </a>
+        )}
+
+        {/* Description */}
+        {author.description && (
+          <div className="mt-4">
+            <p
+              className={`text-sm sm:text-base text-gray-600 dark:text-gray-400 leading-relaxed whitespace-pre-line ${
+                !expanded && hasLongDescription ? 'line-clamp-4' : ''
+              }`}
+            >
+              {author.description}
+            </p>
+            {hasLongDescription && (
+              <button
+                onClick={() => setExpanded(!expanded)}
+                className="mt-1 text-sm font-medium text-indigo-600 dark:text-indigo-400 hover:text-indigo-800 dark:hover:text-indigo-300 transition-colors"
+              >
+                {expanded ? 'Show less' : 'Read more'}
+              </button>
+            )}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
+
+export function AuthorDetailSkeleton() {
+  return (
+    <div className="animate-pulse flex flex-col sm:flex-row items-center sm:items-start gap-6 sm:gap-8">
+      {/* Portrait skeleton */}
+      <div className="flex-shrink-0">
+        <div className="w-36 h-36 sm:w-44 sm:h-44 lg:w-52 lg:h-52 rounded-full bg-gradient-to-br from-gray-200 to-gray-300 dark:from-gray-700 dark:to-gray-800">
+          <div className="w-full h-full rounded-full relative overflow-hidden">
+            <div className="absolute inset-0 -translate-x-full animate-[shimmer_2s_infinite] bg-gradient-to-r from-transparent via-white/20 to-transparent" />
+          </div>
+        </div>
+      </div>
+
+      {/* Info skeleton */}
+      <div className="flex-1 min-w-0 text-center sm:text-left space-y-4">
+        <div className="h-9 bg-gray-200 dark:bg-gray-700 rounded-lg w-64 mx-auto sm:mx-0" />
+        <div className="flex gap-2 justify-center sm:justify-start">
+          <div className="h-6 w-20 bg-gray-200 dark:bg-gray-700 rounded-full" />
+          <div className="h-6 w-24 bg-gray-200 dark:bg-gray-700 rounded-full" />
+          <div className="h-6 w-16 bg-gray-200 dark:bg-gray-700 rounded-full" />
+        </div>
+        <div className="space-y-2">
+          <div className="h-4 bg-gray-200 dark:bg-gray-700 rounded w-full" />
+          <div className="h-4 bg-gray-200 dark:bg-gray-700 rounded w-5/6" />
+          <div className="h-4 bg-gray-200 dark:bg-gray-700 rounded w-4/6" />
+        </div>
+      </div>
+    </div>
+  );
+}