feat: 新增 Android 移动端 head 与共享移动壳（组件面板）

LanMountainDesktop.Mobile.Android/MainActivity.cs

@@ -0,0 +1,19 @@
+using Android.App;
+using Android.Content.PM;
+using Avalonia.Android;
+
+namespace LanMountainDesktop.Mobile.Android;
+
+/// <summary>
+/// Android 入口 Activity。承载 MobileApp（单视图组件面板）。
+/// Avalonia 12 起 AppBuilder 定制移至 <see cref="MobileAndroidApplication"/>。
+/// </summary>
+[Activity(
+    Label = "阑山桌面",
+    Theme = "@style/MyTheme.NoActionBar",
+    Icon = "@drawable/icon",
+    MainLauncher = true,
+    ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize | ConfigChanges.UiMode)]
+public class MainActivity : AvaloniaMainActivity
+{
+}