feat: start

src/Ursa/Controls/MessageBox/MessageBox.cs

@@ -0,0 +1,12 @@
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+
+namespace Ursa.Controls.MessageBox;
+
+public static class MessageBox
+{
+    public static async Task ShowAsync(string message)
+    {
+        var messageWindow = new MessageBoxWindow();
+    }
+}

src/Ursa/Controls/MessageBox/MessageBoxWindow.cs

@@ -0,0 +1,15 @@
+using Avalonia.Controls;
+using Avalonia.Platform;
+
+namespace Ursa.Controls.MessageBox;
+
+public class MessageBoxWindow: Window
+{
+    protected override Type StyleKeyOverride => typeof(MessageBoxWindow);
+
+    static MessageBoxWindow()
+    {
+        ExtendClientAreaChromeHintsProperty.OverrideDefaultValue<MessageBoxWindow>(ExtendClientAreaChromeHints
+            .NoChrome);
+    }
+}