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/app/books/[bookId]/page.tsx

@@ -1,7 +1,7 @@
 import { Suspense } from "react";
 import { ClientBookPage } from "@/components/reader/ClientBookPage";
 import { BookSkeleton } from "@/components/skeletons/BookSkeleton";
-import { BookService } from "@/lib/services/book.service";
+import { getProvider } from "@/lib/providers/provider.factory";
 import { ERROR_CODES } from "@/constants/errorCodes";
 import { AppError } from "@/utils/errors";
 import { redirect } from "next/navigation";
@@ -11,23 +11,30 @@ export default async function BookPage({ params }: { params: Promise<{ bookId: s
   const { bookId } = await params;
 
   try {
-    // SSR: Fetch directly on server instead of client-side XHR
-    const data = await BookService.getBook(bookId);
+    const provider = await getProvider();
+    if (!provider) redirect("/settings");
+
+    const book = await provider.getBook(bookId);
+    const pages = Array.from({ length: book.pageCount }, (_, i) => i + 1);
+
     let nextBook = null;
     try {
-      nextBook = await BookService.getNextBook(bookId, data.book.seriesId);
+      nextBook = await provider.getNextBook(bookId);
     } catch (error) {
       logger.warn({ err: error, bookId }, "Failed to fetch next book, continuing without it");
     }
 
     return (
       <Suspense fallback={<BookSkeleton />}>
-        <ClientBookPage bookId={bookId} initialData={{ ...data, nextBook }} />
+        <ClientBookPage bookId={bookId} initialData={{ book, pages, nextBook }} />
       </Suspense>
     );
   } catch (error) {
     // If config is missing, redirect to settings
-    if (error instanceof AppError && error.code === ERROR_CODES.KOMGA.MISSING_CONFIG) {
+    if (error instanceof AppError && (
+      error.code === ERROR_CODES.KOMGA.MISSING_CONFIG ||
+      error.code === ERROR_CODES.STRIPSTREAM.MISSING_CONFIG
+    )) {
       redirect("/settings");
     }