fix(frontend): add missing 'new' to EventEmitter instantiations

The Angular production build was failing with TS2348 errors because
EventEmitter<void>() was used without the 'new' keyword. This is not
valid TypeScript — EventEmitter is a constructor class, not a callable
value.

Fixes:
- src/app/admin/admin-users-tab.component.ts: added 'new' to saved and
  closed EventEmitter properties

src/app/admin/admin-users-tab.component.ts

@@ -17,8 +17,8 @@ export class AdminUsersTabComponent implements OnChanges {
   private cdr = inject(ChangeDetectorRef);
   private adminUserService = inject(AdminUserService);
 
-  readonly saved = EventEmitter<void>();
-  readonly closed = EventEmitter<void>();
+  readonly saved = new EventEmitter<void>();
+  readonly closed = new EventEmitter<void>();
 
   @Input() editItem: AdminUser | null = null;