bug fix

angular/src/app/_views/trip/trip-detail/trip-detail.component.ts

@@ -219,18 +219,19 @@ export class TripDetailComponent implements OnInit, AfterViewInit {
     }
 
     addNewUserTrip() {
-        // Create a new empty user trip with an empty user object as a placeholder
-        const newUserTrip: UserTripJsonld = {
+        // Erstelle ein unvollständiges Objekt (ohne user-Property)
+        const newUserTrip: any = {
             trip: {
                 'id': this.trip.id
             } as TripJsonld,
-            user: {} as UserJsonld // Empty user object as placeholder
+            user: null
         };
 
-        this.userTrips.push(newUserTrip);
+        // Füge es als UserTripJsonld hinzu
+        this.userTrips.push(newUserTrip as UserTripJsonld);
         this.userForms.push(this.createUserForm());
 
-        // Force update in the next event loop to properly initialize the search-select
+        // Rest unverändert...
         setTimeout(() => {
             if (this.searchSelects) {
                 const lastSelect = this.searchSelects.last;