Extend repository methods and synchronization logic with existence checks for books, chapters, characters, and related entities

- Add methods to verify the existence of acts, plot points, incidents, worlds, characters, locations, and their sub-elements in repositories.
- Update `syncBookFromServerToClient` to integrate existence checks with insert or update logic.
- Enhance multilingual error handling across repository methods.

electron/database/repositories/book.repository.ts

@@ -2352,4 +2352,93 @@ export default class BookRepo {
             }
         }
     }
+    static actSummarizeExist(userId: string, bookId: string, act_index: number,lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result:QueryResult|null = db.get('SELECT 1 FROM book_act_summaries WHERE user_id =? AND book_id =? AND act_index = ?', [userId, bookId, act_index]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence du résumé de l'acte.` : `Unable to check act summary existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
+    
+    static plotPointExist(userId: string, bookId: string, plot_point_id: string,lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result:QueryResult|null = db.get('SELECT 1 FROM book_plot_points WHERE author_id =? AND book_id =? AND plot_point_id =?', [userId, bookId, plot_point_id]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence du point de intrigue.` : `Unable to check plot point existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
+    
+    static incidentExist(userId: string, bookId: string, incident_id: string,lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result: QueryResult | null = db.get('SELECT 1 FROM book_incidents WHERE book_id=? AND incident_id=? AND author_id=?', [bookId, incident_id, userId]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence de l'incident.` : `Unable to check incident existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
+    
+    static worldExist(userId: string, bookId: string, world_id: string,lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result: QueryResult | null = db.get('SELECT 1 FROM `book_world` WHERE `world_id`=? AND `author_id`=? AND `book_id`=?', [world_id, userId, bookId]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence du monde.` : `Unable to check world existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
+    
+    static worldElementExist(userId: string, world_id: string, element_id: string, lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result: QueryResult | null = db.get('SELECT 1 FROM `book_world_elements` WHERE `element_id`=? AND `world_id`=? AND `user_id`=?', [element_id, world_id, userId]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence de l'élément du monde.` : `Unable to check world element existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
+    
+    static issueExist(userId: string, bookId: string, issue_id: string,lang: "fr" | "en"): boolean {
+        try {
+            const db: Database = System.getDb();
+            const result: QueryResult | null = db.get('SELECT 1 FROM `book_issues` WHERE `issue_id`=? AND `author_id`=? AND `book_id`=?', [issue_id, userId, bookId]) || null;
+            return result !== null;
+        } catch (e: unknown) {
+            if (e instanceof Error) {
+                console.error(`DB Error: ${e.message}`);
+                throw new Error(lang === 'fr' ? `Impossible de vérifier l'existence du problème.` : `Unable to check issue existence.`);
+            } else {
+                throw new Error(lang === 'fr' ? "Une erreur inconnue s'est produite." : "An unknown error occurred.");
+            }
+        }
+    }
 }