Back closes what is open

On a phone the Back button left the page under an open menu, sheet or dialog. An open overlay now says so (new
IDOverlayHost, cascaded by MainLayout; OverlayService keeps them newest last): DModal and DDropdown through the
cascade, so the D components stay free of app services, and the nav menu, PhoneSheet and the full-screen globe through
the service. MainLayout's location-changing handler lets Back close the newest overlay instead of leaving the page; a
link followed or the app's own navigation (signing out after its question, say) closes them all and goes on. Blazor
can't tell Back from the app's navigation, so a capture-phase popstate listener in main.js marks Back
(AppStatusService.TookBack). No history entries are pushed. Phone flow: Back closes the menu, a card's More sheet, the
composer and the full-screen globe one after another without leaving the feed, and with nothing open goes back.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Components/Feed/GlobePanel.razor

@@ -82,8 +82,11 @@
 	[Parameter] public bool Expanded { get; set; }
 	[Parameter] public EventCallback<bool> ExpandedChanged { get; set; }
 
+	[Inject] OverlayService Overlays { get; set; }
+
 	ElementReference closeButton;
 	ElementReference expandButton;
+	IDisposable overlay;
 	bool focusClose;
 	bool focusExpand;
 
@@ -115,7 +118,18 @@
 
 	protected override void OnInitialized() => IsLoading = false;
 
-	protected override void OnParametersSet() => postsHandedOver = true;
+	protected override void OnParametersSet()
+	{
+		postsHandedOver = true;
+		// full screen, the Back button closes it
+		if (Expanded && overlay is null)
+			overlay = Overlays.Open(() => InvokeAsync(Close));
+		else if (!Expanded && overlay is not null)
+		{
+			overlay.Dispose();
+			overlay = null;
+		}
+	}
 
 	protected override async Task OnAfterRenderAsync(bool firstRender)
 	{
@@ -323,6 +337,7 @@
 
 	public override async ValueTask DisposeAsync()
 	{
+		overlay?.Dispose();
 		await cancellation.CancelAsync();
 		cancellation.Dispose();
 		statsTimer?.Dispose();