feat: add multi-provider support (Komga + Stripstream Librarian)

- Introduce provider abstraction layer (IMediaProvider, KomgaProvider, StripstreamProvider)
- Add Stripstream Librarian as second media provider with full feature parity
- Migrate all pages and components from direct Komga services to provider factory
- Remove dead service code (BaseApiService, HomeService, LibraryService, SearchService, TestService)
- Fix library/series page-based pagination for both providers (Komga 0-indexed, Stripstream 1-indexed)
- Fix unread filter and search on library page for both providers
- Fix read progress display for Stripstream (reading_status mapping)
- Fix series read status (books_read_count) for Stripstream
- Add global search with series results for Stripstream (series_hits from Meilisearch)
- Fix thumbnail proxy to return 404 gracefully instead of JSON on upstream error
- Replace duration-based cache debug detection with x-nextjs-cache header

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/reader/ClientBookPage.tsx

@@ -5,16 +5,16 @@ import { ClientBookWrapper } from "./ClientBookWrapper";
 import { BookSkeleton } from "@/components/skeletons/BookSkeleton";
 import { ErrorMessage } from "@/components/ui/ErrorMessage";
 import { ERROR_CODES } from "@/constants/errorCodes";
-import type { KomgaBook } from "@/types/komga";
+import type { NormalizedBook } from "@/lib/providers/types";
 import logger from "@/lib/logger";
 import { getBookData } from "@/app/actions/books";
 
 interface ClientBookPageProps {
   bookId: string;
   initialData?: {
-    book: KomgaBook;
+    book: NormalizedBook;
     pages: number[];
-    nextBook: KomgaBook | null;
+    nextBook: NormalizedBook | null;
   };
   initialError?: string;
 }
@@ -23,9 +23,9 @@ export function ClientBookPage({ bookId, initialData, initialError }: ClientBook
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
   const [data, setData] = useState<{
-    book: KomgaBook;
+    book: NormalizedBook;
     pages: number[];
-    nextBook: KomgaBook | null;
+    nextBook: NormalizedBook | null;
   } | null>(null);
 
   // Use SSR data if available