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/hooks/useThumbnails.ts

@@ -1,8 +1,8 @@
 import { useState, useCallback, useEffect } from "react";
-import type { KomgaBook } from "@/types/komga";
+import type { NormalizedBook } from "@/lib/providers/types";
 
 interface UseThumbnailsProps {
-  book: KomgaBook;
+  book: NormalizedBook;
   currentPage: number;
 }
 
@@ -16,9 +16,13 @@ export const useThumbnails = ({ book, currentPage }: UseThumbnailsProps) => {
 
   const getThumbnailUrl = useCallback(
     (pageNumber: number) => {
+      // Derive page URL from the book's thumbnailUrl provider pattern
+      if (book.thumbnailUrl.startsWith("/api/stripstream/")) {
+        return `/api/stripstream/images/books/${book.id}/pages/${pageNumber}`;
+      }
       return `/api/komga/images/books/${book.id}/pages/${pageNumber}/thumbnail?zero_based=true`;
     },
-    [book.id]
+    [book.id, book.thumbnailUrl]
   );
 
   // Mettre à jour les thumbnails visibles autour de la page courante