refactor(lottery): improve code structure and readability

frontend/src/app/service/user.service.ts

@@ -13,6 +13,19 @@ export class UserService {
   private http: HttpClient = inject(HttpClient);
   private authService = inject(AuthService);
 
+  constructor() {
+    // Initialize with the current user from AuthService if available
+    const currentUser = this.authService.getUser();
+    if (currentUser) {
+      this.currentUserSubject.next(currentUser);
+    }
+
+    // Subscribe to auth service user updates
+    this.authService.userSubject.subscribe(user => {
+      this.currentUserSubject.next(user);
+    });
+  }
+
   public getCurrentUser(): Observable<User | null> {
     return this.http.get<User | null>('/backend/users/me').pipe(
       catchError(() => EMPTY),