add graceful fallback for non-dev environment settings file

Author: LeftofZen

AvaGui/Models/ObjectEditorModel.cs

@@ -54,7 +54,7 @@ public class ObjectEditorModel
 
 		public static string SettingsPath => Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), ApplicationName);
 
-		public static string SettingsFile => Path.Combine(SettingsPath, Environment.GetEnvironmentVariable("ENV_SETTINGS_FILE")!); // "settings-dev.json" for dev, "settings.json" for prod
+		public static string SettingsFile => Path.Combine(SettingsPath, Environment.GetEnvironmentVariable("ENV_SETTINGS_FILE") ?? "settings.json"); // "settings-dev.json" for dev, "settings.json" for prod
 
 		public ObservableCollection<LogLine> LoggerObservableLogs = [];
 

AvaGui/ViewModels/FolderTreeViewModel.cs

@@ -53,7 +53,6 @@ public class FolderTreeViewModel : ReactiveObject
 
 		public ReactiveCommand<Unit, Task> RefreshDirectoryItems { get; }
 
-		[Reactive]
 		public ObservableCollection<ObjectDisplayMode> DisplayModeItems { get; } = [.. Enum.GetValues<ObjectDisplayMode>()];
 
 		[Reactive]