Convert commands to AsyncRelayCommand for proper async/await pattern

Co-authored-by: JusterZhu <11714536+JusterZhu@users.noreply.github.com>

Author: Copilot

src/ViewModels/ExtensionViewModel.cs

@@ -25,8 +25,8 @@ public class ExtensionViewModel : ObservableObject
     private RelayCommand? _clearCommand;
     private AsyncRelayCommand? _selectDependenciesCommand;
     private ExtensionDependencySelectionModel? _selectedDependency;
-    private RelayCommand<CustomPropertyModel>? _removeCustomPropertyCommand;
-    private RelayCommand? _addCustomPropertyCommand;
+    private AsyncRelayCommand<CustomPropertyModel>? _removeCustomPropertyCommand;
+    private AsyncRelayCommand? _addCustomPropertyCommand;
     private string? _newCustomPropertyKey;
     private string? _newCustomPropertyValue;
 
@@ -77,14 +77,14 @@ public ExtensionDependencySelectionModel? SelectedDependency
         set => SetProperty(ref _selectedDependency, value);
     }
 
-    public RelayCommand<CustomPropertyModel> RemoveCustomPropertyCommand
+    public AsyncRelayCommand<CustomPropertyModel> RemoveCustomPropertyCommand
     {
-        get => _removeCustomPropertyCommand ??= new RelayCommand<CustomPropertyModel>(RemoveCustomPropertyAction);
+        get => _removeCustomPropertyCommand ??= new AsyncRelayCommand<CustomPropertyModel>(RemoveCustomPropertyAction);
     }
 
-    public RelayCommand AddCustomPropertyCommand
+    public AsyncRelayCommand AddCustomPropertyCommand
     {
-        get => _addCustomPropertyCommand ??= new RelayCommand(AddCustomPropertyAction, CanAddCustomProperty);
+        get => _addCustomPropertyCommand ??= new AsyncRelayCommand(AddCustomPropertyAction, CanAddCustomProperty);
     }
 
     public string? NewCustomPropertyKey
@@ -311,7 +311,7 @@ private bool CanAddCustomProperty()
                !string.IsNullOrWhiteSpace(NewCustomPropertyValue);
     }
 
-    private async void AddCustomPropertyAction()
+    private async Task AddCustomPropertyAction()
     {
         try
         {
@@ -357,7 +357,7 @@ private async void AddCustomPropertyAction()
         }
     }
 
-    private async void RemoveCustomPropertyAction(CustomPropertyModel? property)
+    private async Task RemoveCustomPropertyAction(CustomPropertyModel? property)
     {
         try
         {
@@ -367,12 +367,6 @@ private async void RemoveCustomPropertyAction(CustomPropertyModel? property)
                 return;
             }
 
-            if (string.IsNullOrWhiteSpace(property.Key))
-            {
-                await MessageBox.ShowAsync("Property key is invalid", "Validation Error", Buttons.OK);
-                return;
-            }
-
             // Remove from dictionary
             if (ConfigModel.CustomProperties.ContainsKey(property.Key))
             {