Update with recovered code from VM binaries (Jan 1)

- ShellDemo: Updated all pages with recovered code, added AppShell.cs
- TodoApp: Updated core files, added converters
- XamlBrowser: Added recovered sample

ShellDemo/MauiProgram.cs

@@ -1,6 +1,4 @@
-// MauiProgram.cs - Shared MAUI app configuration
-// Works across all platforms (iOS, Android, Windows, Linux)
-
+using Microsoft.Maui.Controls.Hosting;
 using Microsoft.Maui.Hosting;
 using Microsoft.Maui.Platform.Linux.Hosting;
 
@@ -8,17 +6,11 @@ namespace ShellDemo;
 
 public static class MauiProgram
 {
-    public static MauiApp CreateMauiApp()
-    {
-        var builder = MauiApp.CreateBuilder();
-        
-        // Configure the app (shared across all platforms)
-        builder.UseMauiApp<App>();
-        
-        // Add Linux platform support
-        // On other platforms, this would be iOS/Android/Windows specific
-        builder.UseLinux();
-        
-        return builder.Build();
-    }
+	public static MauiApp CreateMauiApp()
+	{
+		MauiAppBuilder obj = MauiApp.CreateBuilder(true);
+		AppHostBuilderExtensions.UseMauiApp<App>(obj);
+		obj.UseLinux();
+		return obj.Build();
+	}
 }