important: keep this pagecontext alive for the duration

if you don't, then eventually, we'll GC this object, and all objects
that took a weak ref on it will throw.

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/CommandProviderWrapper.cs

@@ -51,12 +51,15 @@ public sealed class CommandProviderWrapper : ICommandProviderContext
 
     public bool SupportsPinning { get; private set; }
 
+    public TopLevelItemPageContext TopLevelPageContext { get; }
+
     public CommandProviderWrapper(ICommandProvider provider, TaskScheduler mainThread)
     {
         // This ctor is only used for in-proc builtin commands. So the Unsafe!
         // calls are pretty dang safe actually.
         _commandProvider = new(provider);
         _taskScheduler = mainThread;
+        TopLevelPageContext = new TopLevelItemPageContext(this, _taskScheduler);
 
         // Hook the extension back into us
         ExtensionHost = new CommandPaletteHost(provider);
@@ -81,6 +84,7 @@ public sealed class CommandProviderWrapper : ICommandProviderContext
     {
         _taskScheduler = mainThread;
         _commandProviderCache = commandProviderCache;
+        TopLevelPageContext = new TopLevelItemPageContext(this, _taskScheduler);
 
         Extension = extension;
         ExtensionHost = new CommandPaletteHost(extension);

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/TopLevelCommandManager.cs

@@ -103,8 +103,7 @@ public partial class TopLevelCommandManager : ObservableObject,
     // May be called from a background thread
     private async Task<IEnumerable<TopLevelViewModel>> LoadTopLevelCommandsFromProvider(CommandProviderWrapper commandProvider)
     {
-        TopLevelItemPageContext pageContext = new(commandProvider, _taskScheduler);
-        WeakReference<IPageContext> weak = new(pageContext);
+        WeakReference<IPageContext> weak = new(commandProvider.TopLevelPageContext);
 
         await commandProvider.LoadTopLevelCommands(_serviceProvider, weak);
 

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/TopLevelItemPageContext.cs

@@ -11,7 +11,7 @@ namespace Microsoft.CmdPal.UI.ViewModels;
 /// Used as the PageContext for top-level items. Top level items are displayed
 /// on the MainListPage, which _we_ own. We need to have a placeholder page
 /// context for each provider that still connects those top-level items to the
-/// CommandProvider they came from. 
+/// CommandProvider they came from.
 /// </summary>
 public partial class TopLevelItemPageContext : IPageContext
 {