fix backdrop not setting properly on launch & limited backdrop options

StabilityMatrix/ViewModels/MainWindowViewModel.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Linq;
 using System.Threading.Tasks;
+using System.Windows;
 using System.Windows.Threading;
 using System.Windows.Shell;
 using CommunityToolkit.Mvvm.ComponentModel;
@@ -88,15 +89,24 @@ public partial class MainWindowViewModel : ObservableObject
 
     private void SetTheme()
     {
+        Application.Current.Dispatcher.BeginInvoke(() =>
+        {
+            if (Application.Current.MainWindow != null)
+            {
+                WindowBackdrop.ApplyBackdrop(Application.Current.MainWindow,
+                    settingsManager.Settings.WindowBackdropType);
+            }
+
             var theme = settingsManager.Settings.Theme;
             switch (theme)
             {
                 case "Dark":
-                Theme.Apply(ThemeType.Dark, WindowBackdropType.Acrylic);
+                    Theme.Apply(ThemeType.Dark, settingsManager.Settings.WindowBackdropType);
                     break;
                 case "Light":
-                Theme.Apply(ThemeType.Light, WindowBackdropType.Acrylic);
+                    Theme.Apply(ThemeType.Light, settingsManager.Settings.WindowBackdropType);
                     break;
             }
+        });
     }
 }

StabilityMatrix/ViewModels/SettingsViewModel.cs

@@ -34,9 +34,7 @@ public partial class SettingsViewModel : ObservableObject
     public ObservableCollection<WindowBackdropType> AvailableBackdrops => new()
     {
         WindowBackdropType.Acrylic,
-        WindowBackdropType.Auto,
         WindowBackdropType.Mica,
-        WindowBackdropType.None,
         WindowBackdropType.Tabbed
     };
     private readonly IContentDialogService contentDialogService;