Minor improvements

src/GuiApp/Avalonia/FileTime.GuiApp/App.axaml.cs

@@ -32,6 +32,7 @@ public class Application : Avalonia.Application
             .ConfigureFont(configuration)
             .RegisterLogging()
             .RegisterServices()
+            .AddSettings()
             .AddViewModels()
             .BuildServiceProvider();
 

src/GuiApp/Avalonia/FileTime.GuiApp/Startup.cs

@@ -49,6 +49,12 @@ public static class Startup
         serviceCollection.TryAddSingleton<IGuiAppState>(s => s.GetRequiredService<GuiAppState>());
         return serviceCollection;
     }
+    
+    internal static IServiceCollection AddSettings(this IServiceCollection serviceCollection)
+    {
+        serviceCollection.TryAddSingleton(new TabPersistenceSettings());
+        return serviceCollection;
+    }
 
     internal static IServiceCollection RegisterServices(this IServiceCollection serviceCollection)
     {