- add handling to hide main window instead of closing it

Mystify/Views/MainWindow.axaml.cs

@@ -1,3 +1,4 @@
+using System.ComponentModel;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
@@ -9,11 +10,21 @@ namespace Mystify.Views
         public MainWindow()
         {
             InitializeComponent();
+            
+            Closing += OnClosing;
+            
 #if DEBUG
             this.AttachDevTools();
 #endif
         }
 
         private void InitializeComponent() => AvaloniaXamlLoader.Load(this);
+        
+        private void OnClosing(object? sender, CancelEventArgs args)
+        {
+            //don't really close main window, just hide it -> notify icon is still there
+            Hide();
+            args.Cancel = true;
+        }
     }
 }