Add language config and locale-aware parsing

Introduce centralized language configuration and wire locale-aware behavior across scraping and ranking. Adds src/lib/constants/language-config.ts with per-language scraping rules, stop words, and character replacements; replaces AudibleRegion.isEnglish with a language field in types and AUDIBLE_REGIONS. Update AudibleService, ebook scraper, processors, and API routes to use getLanguageForRegion so Anna's Archive searches, scraping selectors, runtime/rating parsing, and ranking use language-specific params and filters. Extend ranking algorithm to accept stopWords and characterReplacements and apply them during normalization and matching. Update UI selects to mark non-English regions and adjust tests accordingly.

tests/processors/search-indexers.processor.test.ts

@@ -8,7 +8,7 @@ import { createPrismaMock } from '../helpers/prisma';
 import { createJobQueueMock } from '../helpers/job-queue';
 
 const prismaMock = createPrismaMock();
-const configMock = vi.hoisted(() => ({ get: vi.fn() }));
+const configMock = vi.hoisted(() => ({ get: vi.fn(), getAudibleRegion: vi.fn().mockResolvedValue('us') }));
 const jobQueueMock = createJobQueueMock();
 const prowlarrMock = vi.hoisted(() => ({ search: vi.fn(), searchWithVariations: vi.fn() }));
 
@@ -35,6 +35,7 @@ vi.mock('@/lib/integrations/audible.service', () => ({
 describe('processSearchIndexers', () => {
   beforeEach(() => {
     vi.clearAllMocks();
+    configMock.getAudibleRegion.mockResolvedValue('us');
   });
 
   it('marks request awaiting_search when no results found', async () => {