Add SharpTreeNode.ReloadChildren for the lazy-subtree reset

The UseNestedNamespaceNodes and HideEmptyMetadataTables handlers both
force a materialised node to re-create its children (clear, re-arm
LazyLoading, EnsureLazyChildren), guarded on it not already being lazy.
That's a general tree-node operation -- a soft, in-place rebuild that
re-runs LoadChildren without reloading the assembly -- so it belongs on
SharpTreeNode next to the lazy contract it builds on, not as a private
helper in the model. Both call sites now use node.ReloadChildren().

Assisted-by: Claude:claude-opus-4-8:Claude Code

ICSharpCode.ILSpyX/TreeView/SharpTreeNode.cs

@@ -374,6 +374,23 @@ namespace ICSharpCode.ILSpyX.TreeView
 			}
 		}
 
+		/// <summary>
+		/// Rebuilds the children of an already-loaded node in place: clears them, re-arms lazy
+		/// loading, and re-runs <see cref="LoadChildren"/>. A no-op for a node that is still lazy
+		/// (it will build fresh on first expand anyway). Use this when external state that
+		/// <see cref="LoadChildren"/> reads has changed and the materialized subtree must be
+		/// regenerated -- e.g. a display setting that alters the tree's shape. Like setting
+		/// <see cref="LazyLoading"/>, this collapses the node.
+		/// </summary>
+		public void ReloadChildren()
+		{
+			if (LazyLoading)
+				return;
+			Children.Clear();
+			LazyLoading = true;
+			EnsureLazyChildren();
+		}
+
 		#endregion
 
 		#region Ancestors / Descendants

ILSpy/AssemblyTree/AssemblyTreeModel.cs

@@ -264,15 +264,9 @@ namespace ILSpy.AssemblyTree
 					break;
 				case nameof(Options.DisplaySettings.UseNestedNamespaceNodes):
 					// Tree shape changes — every loaded AssemblyTreeNode's namespace subtree
-					// needs rebuilding. Reset Children + LazyLoading and re-trigger the load.
+					// needs rebuilding.
 					foreach (var asm in Root.Children.OfType<TreeNodes.AssemblyTreeNode>())
-					{
-						if (asm.LazyLoading)
-							continue;
-						asm.Children.Clear();
-						asm.LazyLoading = true;
-						asm.EnsureLazyChildren();
-					}
+						asm.ReloadChildren();
 					// AssemblyListPane caches a snapshot of each expanded node's children via
 					// the HierarchicalOptions.ChildrenSelector — mid-expand mutations of
 					// node.Children aren't observed. Re-raising Root forces BindTree to fire,
@@ -294,12 +288,7 @@ namespace ILSpy.AssemblyTree
 		{
 			if (node is Metadata.MetadataTablesTreeNode tables)
 			{
-				if (!tables.LazyLoading)
-				{
-					tables.Children.Clear();
-					tables.LazyLoading = true;
-					tables.EnsureLazyChildren();
-				}
+				tables.ReloadChildren();
 				return;
 			}
 			if (node.LazyLoading)