Add per-user ignored audiobooks feature

Introduce a per-user "ignored audiobooks" feature to suppress auto-requests. Changes include:

- Database: add Prisma model IgnoredAudiobook and SQL migration to create ignored_audiobooks table with indexes and FK to users.
- Backend: new API routes to list, add, delete, and check ignored audiobooks (/api/user/ignored-audiobooks, /check/:asin, /:id). Add annotateWithIgnoreStatus utility and integrate it into multiple audiobook list endpoints (popular, new-releases, category, search, authors, series).
- Request creator: add ignore-list check (with sibling-ASIN expansion) and a bypassIgnore option for manual requests; return an 'ignored' reason when blocked.
- Frontend: hooks (useIsIgnored, useToggleIgnore, useIgnoredList) and UI updates — AudiobookCard shows an "Ignored" indicator and AudiobookDetailsModal adds an ignore toggle and propagates local state changes.
- Misc: adjust deduplication duration tolerance (to 5% / min 10 minutes), tweak SWR refresh intervals for shelves/syncing, and small logging/info updates.
- Tests: add unit tests for request-creator ignore logic and update existing tests/mocks to account for ignore annotation; extend prisma test helper with ignoredAudiobook mock.

This commit implements the ignore-list end-to-end (DB, server, client, and tests) so users can ignore specific ASINs and have auto-request flows respect that preference.

src/lib/utils/deduplicate-audiobooks.ts

@@ -6,7 +6,7 @@
  * under different ASINs (publisher re-listings, rights transfers, etc.).
  *
  * Dedup key: normalized title + normalized narrator
- * Duration tolerance: max(longerDuration * 0.01, 5) minutes
+ * Duration tolerance: max(longerDuration * 0.05, 10) minutes
  * Missing duration treated as compatible (graceful degradation).
  */
 
@@ -95,13 +95,13 @@ function normalizeNarrator(narrator?: string): string {
 
 /**
  * Check if two durations are compatible (represent the same recording).
- * Tolerance: max(longerDuration * 0.01, 5) minutes.
+ * Tolerance: max(longerDuration * 0.05, 10) minutes.
  * Missing duration on either side is treated as compatible.
  */
 export function areDurationsCompatible(a?: number, b?: number): boolean {
   if (a == null || b == null) return true;
   const longer = Math.max(a, b);
-  const tolerance = Math.max(longer * 0.01, 5);
+  const tolerance = Math.max(longer * 0.05, 10);
   return Math.abs(a - b) <= tolerance;
 }
 

src/lib/utils/ignored-audiobooks.ts

@@ -0,0 +1,37 @@
+/**
+ * Component: Ignored Audiobooks Utility
+ * Documentation: documentation/features/ignored-audiobooks.md
+ *
+ * Shared utility for annotating audiobook lists with per-user ignore status.
+ * Uses a single bulk query for the user's full ignore list, then annotates in-memory.
+ */
+
+import { prisma } from '@/lib/db';
+
+/**
+ * Annotate an array of audiobook objects with `isIgnored: boolean`.
+ * Fetches the user's full ignore list in one query and matches by ASIN.
+ *
+ * If userId is undefined (unauthenticated), all books get `isIgnored: false`.
+ */
+export async function annotateWithIgnoreStatus<T extends { asin: string }>(
+  audiobooks: T[],
+  userId?: string
+): Promise<(T & { isIgnored: boolean })[]> {
+  if (!userId || audiobooks.length === 0) {
+    return audiobooks.map((book) => ({ ...book, isIgnored: false }));
+  }
+
+  // Single query: get all ASINs this user has ignored
+  const ignoredEntries = await prisma.ignoredAudiobook.findMany({
+    where: { userId },
+    select: { asin: true },
+  });
+
+  const ignoredAsinSet = new Set(ignoredEntries.map((e) => e.asin));
+
+  return audiobooks.map((book) => ({
+    ...book,
+    isIgnored: ignoredAsinSet.has(book.asin),
+  }));
+}