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/app/api/authors/search/route.ts

@@ -0,0 +1,91 @@
+/**
+ * Component: Author Search API Route
+ * Documentation: documentation/integrations/audible.md
+ */
+
+import { NextRequest, NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/middleware/auth';
+import { getConfigService } from '@/lib/services/config.service';
+import { AUDIBLE_REGIONS, DEFAULT_AUDIBLE_REGION, AudibleRegion } from '@/lib/types/audible';
+import { RMABLogger } from '@/lib/utils/logger';
+import {
+  AudnexusAuthorDetail,
+  searchAuthors,
+  fetchAuthorDetail,
+} from '@/lib/integrations/audnexus-authors';
+
+const logger = RMABLogger.create('API.Authors.Search');
+
+/**
+ * GET /api/authors/search?name=Brandon Sanderson
+ * Search for authors on Audnexus, deduplicate, and return enriched details
+ */
+export async function GET(request: NextRequest) {
+  try {
+    // Require authentication
+    const currentUser = getCurrentUser(request);
+    if (!currentUser) {
+      return NextResponse.json(
+        { error: 'Unauthorized', message: 'Authentication required' },
+        { status: 401 }
+      );
+    }
+
+    const name = request.nextUrl.searchParams.get('name');
+
+    if (!name || name.trim().length === 0) {
+      return NextResponse.json(
+        { error: 'ValidationError', message: 'Author name is required' },
+        { status: 400 }
+      );
+    }
+
+    // Get configured Audible region
+    const configService = getConfigService();
+    const audibleRegion: AudibleRegion = await configService.getAudibleRegion();
+    const region = AUDIBLE_REGIONS[audibleRegion]?.audnexusParam || AUDIBLE_REGIONS[DEFAULT_AUDIBLE_REGION].audnexusParam;
+
+    logger.info(`Searching authors: "${name}" (region: ${region})`);
+
+    // Step 1: Search for authors (returns list with potential duplicates)
+    const searchResults = await searchAuthors(name.trim(), region);
+
+    if (searchResults.length === 0) {
+      return NextResponse.json({
+        success: true,
+        authors: [],
+        query: name.trim(),
+      });
+    }
+
+    // Step 2: Fetch details for all unique authors in parallel
+    const detailPromises = searchResults.map(author => fetchAuthorDetail(author.asin, region));
+    const detailResults = await Promise.all(detailPromises);
+
+    // Step 3: Build enriched results, filtering out any failed fetches
+    const authors = detailResults
+      .filter((detail): detail is AudnexusAuthorDetail => detail !== null)
+      .map(detail => ({
+        asin: detail.asin,
+        name: detail.name,
+        description: detail.description || undefined,
+        image: detail.image || undefined,
+        genres: detail.genres?.map(g => g.name).slice(0, 3) || [],
+        similarCount: detail.similar?.length || 0,
+      }));
+
+    logger.info(`Author search complete: "${name}" → ${authors.length} results`);
+
+    return NextResponse.json({
+      success: true,
+      authors,
+      query: name.trim(),
+    });
+  } catch (error) {
+    logger.error('Failed to search authors', { error: error instanceof Error ? error.message : String(error) });
+    return NextResponse.json(
+      { error: 'SearchError', message: 'Failed to search authors' },
+      { status: 500 }
+    );
+  }
+}