Remove CharacterComponent and CharacterDetail components

- Deleted `CharacterComponent` and `CharacterDetail` files from the project.
- Refactored related logic to improve code maintainability and reduce redundancy.

electron/database/repositories/book.repository.ts

@@ -123,7 +123,7 @@ export default class BookRepo {
         let book: BookQuery;
         try {
             const db: Database = System.getDb();
-            const query: string = 'SELECT book_id, author_id, title, summary, sub_title, cover_image, desired_release_date, desired_word_count, words_count FROM erit_books WHERE book_id=? AND author_id=?';
+            const query: string = 'SELECT book_id, author_id, title, summary, sub_title, cover_image, desired_release_date, desired_word_count, words_count, serie_id FROM erit_books WHERE book_id=? AND author_id=?';
             const params: SQLiteValue[] = [bookId, userId];
             book = db.get(query, params) as BookQuery;
         } catch (error: unknown) {
@@ -456,4 +456,40 @@ export default class BookRepo {
             throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
         }
     }
+
+    static isBookExist(userId: string, bookId: string, lang: 'fr' | 'en'): boolean {
+        try {
+            const db: Database = System.getDb();
+            const query: string = 'SELECT 1 FROM erit_books WHERE author_id = ? AND book_id = ? LIMIT 1';
+            const params: SQLiteValue[] = [userId, bookId];
+            const result = db.get(query, params);
+            return result !== undefined && result !== null;
+        } catch (error: unknown) {
+            if (error instanceof Error) {
+                console.error(`DB Error: ${error.message}`);
+            }
+            return false;
+        }
+    }
+
+    /**
+     * Retrieves the series_id for a book from series_books table.
+     * @param bookId - The book identifier
+     * @param lang - The language for error messages
+     * @returns The series_id or null if book is not in a series
+     */
+    static fetchBookSeriesId(bookId: string, lang: 'fr' | 'en'): string | null {
+        try {
+            const db: Database = System.getDb();
+            const query: string = 'SELECT series_id FROM series_books WHERE book_id = ? LIMIT 1';
+            const params: SQLiteValue[] = [bookId];
+            const result = db.get(query, params) as { series_id: string } | undefined;
+            return result?.series_id || null;
+        } catch (error: unknown) {
+            if (error instanceof Error) {
+                console.error(`DB Error: ${error.message}`);
+            }
+            return null;
+        }
+    }
 }