fixed book loading on anilist entries

src/books/books.service.ts

@@ -271,10 +271,9 @@ export async function getChaptersForBook(id: string): Promise<{ chapters: Chapte
     let searchTitle: string = "";
 
     if (!isNaN(Number(id))) {
-        bookData = await fetchBookMetadata(id);
-        if (!bookData) {
-            return { chapters: [] };
-        }
+        const result = await getBookById(id);
+        if (!result || "error" in result) return { chapters: [] }
+        bookData = result;
         const titles = [bookData.title.english, bookData.title.romaji].filter(Boolean) as string[];
         searchTitle = titles[0];
     }