refactor: remove caching-related API endpoints and configurations, update preferences structure, and clean up unused services

src/components/reader/PhotoswipeReader.tsx

@@ -75,8 +75,6 @@ export function PhotoswipeReader({ book, pages, onClose, nextBook }: BookReaderP
   }, []);
 
   // Prefetch current and next pages
-  // Deduplication in useImageLoader prevents redundant requests
-  // Server queue (RequestQueueService) handles concurrency limits
   useEffect(() => {
     // Prefetch pages starting from current page
     prefetchPages(currentPage, prefetchCount);