Refactor PublicWalkRequestCreateViewModel to improve dog selection logic and ensure UI updates correctly

gehGassiApp/gehGassiApp/ViewModels/Walks/PublicWalkRequestCreateViewModel.cs

@@ -526,7 +526,7 @@ namespace gehGassiApp.ViewModels.Walks
             }
         }
 
-#endregion
+        #endregion
 
         /// <summary>
         /// Laden der initialen Daten
@@ -597,6 +597,8 @@ namespace gehGassiApp.ViewModels.Walks
                     CheckSubscription(AppMode.DogOwner);
                 }
             }
+                    DogSelectionChanged();
+            
         }
 
         /// <summary>
@@ -615,10 +617,22 @@ namespace gehGassiApp.ViewModels.Walks
             {
                 Dogs = dogs.ToObservableCollection();
                 SelectedDog = Dogs.FirstOrDefault();
+                
+                // Ersten Hund automatisch zur Auswahl hinzufügen
+                if (Dogs.Count > 0)
+                {
+                    SelectedDogs.Clear();
+                    SelectedDogs.Add(Dogs.First());
+                    DogsSelected = true;
+                    
+                    // DogSelectionChanged Command manuell auslösen für UI-Update
+                }
             }
             else
             {
                 Dogs?.Clear();
+                SelectedDogs?.Clear();
+                DogsSelected = false;
             }
 
             HasNoDog = Dogs.Count == 0;