Add watched series/authors feature

Introduce watched lists for series and authors end-to-end.

- Add DB migration to create watched_series and watched_authors tables with indexes and foreign keys.
- Implement API routes: GET/POST for listing/adding and DELETE by id for both /api/user/watched-series and /api/user/watched-authors. Validation, ownership checks, and immediate targeted job triggers are included.
- Add client hooks (useWatchedSeries, useWatchedAuthors) with add/delete helpers and SWR revalidation.
- Add UI components: WatchButton (toggle/confirm) and WatchedListsSection for profile display and removal UX.
- Add processor (check-watched-lists.processor) and service (watched-lists.service) to scrape Audible, deduplicate, check library ownership, and auto-create requests; supports targeted checks for newly watched items.
- Include tests for the watched-lists service.

These changes implement the watched-lists feature to let users watch series/authors and have the system automatically detect and request new releases.

tests/services/job-queue.service.test.ts

@@ -22,6 +22,7 @@ const processorsMock = vi.hoisted(() => ({
   processRetryFailedImports: vi.fn().mockResolvedValue('ok'),
   processCleanupSeededTorrents: vi.fn().mockResolvedValue('ok'),
   processSyncGoodreadsShelves: vi.fn().mockResolvedValue('ok'),
+  processCheckWatchedLists: vi.fn().mockResolvedValue('ok'),
   // Ebook processors
   processSearchEbook: vi.fn().mockResolvedValue('ok'),
   processStartDirectDownload: vi.fn().mockResolvedValue('ok'),
@@ -120,6 +121,10 @@ vi.mock('@/lib/processors/sync-goodreads-shelves.processor', () => ({
   processSyncGoodreadsShelves: processorsMock.processSyncGoodreadsShelves,
 }));
 
+vi.mock('@/lib/processors/check-watched-lists.processor', () => ({
+  processCheckWatchedLists: processorsMock.processCheckWatchedLists,
+}));
+
 // Ebook processors
 vi.mock('@/lib/processors/search-ebook.processor', () => ({
   processSearchEbook: processorsMock.processSearchEbook,
@@ -565,6 +570,7 @@ describe('JobQueueService', () => {
     expect(processorsMock.processRetryFailedImports).toHaveBeenCalled();
     expect(processorsMock.processCleanupSeededTorrents).toHaveBeenCalled();
     expect(processorsMock.processSyncGoodreadsShelves).toHaveBeenCalled();
+    expect(processorsMock.processCheckWatchedLists).toHaveBeenCalled();
   });
 
   it('returns repeatable jobs from the queue', async () => {