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.

tests/helpers/prisma.ts

@@ -57,6 +57,7 @@ export const createPrismaMock = () => ({
   watchedAuthor: createModelMock(),
   userHomeSection: createModelMock(),
   audibleCacheCategory: createModelMock(),
+  ignoredAudiobook: createModelMock(),
   $queryRaw: vi.fn(),
   $transaction: vi.fn(),
   $disconnect: vi.fn(),