Refactor API routes and remove unused endpoints

- Deleted the following API routes:
  - `upload-cover`
  - `truyen/[id]/chapters`
  - `truyen/[id]/comments`
  - `truyen/[id]/rate`
  - `truyen/suggest`
  - `user/bookmarks`
  - `user/recommendations`
  - `user/settings`

- Updated `chapter-client.tsx` and `novel-client.tsx` to handle error messages more gracefully.
- Adjusted pagination logic in `tim-kiem/page.tsx` to improve user experience.
- Added support for additional search parameters in the search functionality.
- Introduced API rewrites in `next.config.mjs` to route requests to a reader API.

app/truyen/[slug]/page.tsx

@@ -101,7 +101,7 @@ export default async function NovelDetailPage({
       volumeTitle: (c as any).volumeTitle ?? null,
       volumeChapterNumber: (c as any).volumeChapterNumber ?? null,
       title: c.title,
-      createdAt: (c.createdAt as Date).toISOString(),
+      createdAt: c.createdAt ? (c.createdAt as Date).toISOString() : new Date().toISOString(),
       views: c.views || 0,
       content: ""
     }))