Re-apply a pre-attach tree selection once the tree loads

A model selection set before the SharpTreeView is attached to the visual tree
(e.g. AnalyzerTreeViewModel.Analyze selects its node, then the pane is shown)
was lost: the ListBox isn't an initialised ItemsControl yet, so the binder's
SelectedItems add silently dropped. Nothing re-applied it, so the analyzed row
showed unselected and keyboard gestures had no current node.

Making SharpTreeView focusable (for first-press Ctrl+A) unmasked this: with the
tree itself taking focus instead of delegating to the selected row's container,
keyboard handlers fell back to SelectedItem, which was empty. Re-sync on the
tree's Loaded event so the selection sticks once the control is ready.

ILSpy/Controls/TreeView/TreeSelectionBinder.cs

@@ -46,15 +46,27 @@ namespace ILSpy.Controls.TreeView
 			this.tree = tree ?? throw new ArgumentNullException(nameof(tree));
 			this.modelSelection = modelSelection ?? throw new ArgumentNullException(nameof(modelSelection));
 			tree.SelectionChanged += OnTreeSelectionChanged;
+			tree.Loaded += OnTreeLoaded;
 			modelSelection.CollectionChanged += OnModelSelectionChanged;
-			// The model may already carry a selection (restored before the view was realised).
+			// The model may already carry a selection (restored, or set by Analyze, before the view
+			// was realised). Apply it now; if the tree isn't attached yet the ListBox drops the
+			// SelectedItems add, so OnTreeLoaded re-applies once it is.
 			if (modelSelection.Count > 0)
 				SyncModelToTree();
 		}
 
+		// A selection applied before the tree was attached doesn't stick (the ListBox isn't an
+		// initialised ItemsControl yet); re-apply once it loads so the row shows selected/focused.
+		void OnTreeLoaded(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+		{
+			if (modelSelection.Count > 0 && tree.SelectedItems!.Count == 0)
+				SyncModelToTree();
+		}
+
 		public void Dispose()
 		{
 			tree.SelectionChanged -= OnTreeSelectionChanged;
+			tree.Loaded -= OnTreeLoaded;
 			modelSelection.CollectionChanged -= OnModelSelectionChanged;
 		}