Initial WinUI switch.

Wino.Core.WinUI/Models/Personalization/SystemAppTheme.cs

@@ -0,0 +1,12 @@
+using System;
+using Wino.Core.Domain.Enums;
+
+namespace Wino.Core.UWP.Models.Personalization;
+
+// Mica - Acrylic.
+public class SystemAppTheme : PreDefinedAppTheme
+{
+    public SystemAppTheme(string themeName, Guid id) : base(themeName, id, "") { }
+
+    public override AppThemeType AppThemeType => AppThemeType.System;
+}