Restore the "Add to main list" entry for auto-loaded assemblies

An on-demand resolved dependency had no way to be promoted into the
assembly list, so it was discarded on the next list reload. Restore the
context entry that clears IsAutoLoaded and re-saves the list.

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

ILSpy.Tests/AssemblyList/AddToMainListContextMenuTests.cs

@@ -0,0 +1,80 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Threading.Tasks;
+
+using Avalonia.Headless.NUnit;
+
+using AwesomeAssertions;
+
+using ICSharpCode.ILSpy.Properties;
+using ICSharpCode.ILSpyX.TreeView;
+
+using ILSpy;
+using ILSpy.AppEnv;
+using ILSpy.TreeNodes;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests;
+
+/// <summary>
+/// The "Add to main list" context entry promotes an auto-loaded (on-demand resolved) dependency into
+/// a permanent member of the assembly list. It is visible only when an auto-loaded assembly is
+/// selected. (Regression: the entry was dropped in the Avalonia port.)
+/// </summary>
+[TestFixture]
+public class AddToMainListContextMenuTests
+{
+	[AvaloniaTest]
+	public async Task AddToMainList_Is_Hidden_For_A_Normal_List_Member()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+		var entry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>().GetEntry(nameof(Resources._AddMainList));
+
+		var asm = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+		Assert.That(asm, Is.Not.Null);
+
+		entry.IsVisible(new TextViewContext { SelectedTreeNodes = new[] { (SharpTreeNode)asm! } })
+			.Should().BeFalse("a normal (non auto-loaded) list member must not show 'Add to main list'");
+	}
+
+	[AvaloniaTest]
+	public async Task AddToMainList_Promotes_An_AutoLoaded_Assembly()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+		var entry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>().GetEntry(nameof(Resources._AddMainList));
+
+		var asm = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+		Assert.That(asm, Is.Not.Null);
+		asm!.LoadedAssembly.IsAutoLoaded = true;
+		try
+		{
+			var context = new TextViewContext { SelectedTreeNodes = new[] { (SharpTreeNode)asm } };
+			entry.IsVisible(context).Should().BeTrue("an auto-loaded assembly is selected");
+
+			entry.Execute(context);
+
+			asm.IsAutoLoaded.Should().BeFalse("the assembly was promoted into the main list");
+		}
+		finally
+		{
+			asm.LoadedAssembly.IsAutoLoaded = false;
+		}
+	}
+}

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -642,5 +642,34 @@ namespace ILSpy.TreeNodes
 				await assemblyTreeModel.LoadDependenciesAsync(context.SelectedTreeNodes);
 			}
 		}
+
+		// Promotes an auto-loaded (on-demand resolved) dependency into a permanent member of the
+		// assembly list, so it survives a list reload. Visible only when an auto-loaded assembly is
+		// selected. Mirrors the previous version's "Add to main list".
+		[ExportContextMenuEntry(Header = nameof(ICSharpCode.ILSpy.Properties.Resources._AddMainList), Category = nameof(ICSharpCode.ILSpy.Properties.Resources.Dependencies), Order = 710)]
+		[System.Composition.Shared]
+		[method: System.Composition.ImportingConstructor]
+		sealed class AddToMainList(AssemblyTree.AssemblyTreeModel assemblyTreeModel) : IContextMenuEntry
+		{
+			public bool IsVisible(TextViewContext context)
+				=> context.SelectedTreeNodes?.OfType<AssemblyTreeNode>().Any(n => n.IsAutoLoaded) == true;
+
+			public bool IsEnabled(TextViewContext context)
+				=> context.SelectedTreeNodes?.OfType<AssemblyTreeNode>().Any() == true;
+
+			public void Execute(TextViewContext context)
+			{
+				if (context.SelectedTreeNodes == null)
+					return;
+				foreach (var node in context.SelectedTreeNodes.OfType<AssemblyTreeNode>())
+				{
+					if (node.LoadedAssembly.HasLoadError)
+						continue;
+					node.LoadedAssembly.IsAutoLoaded = false;
+					node.RaisePropertyChanged(nameof(ILSpyTreeNode.IsAutoLoaded));
+				}
+				assemblyTreeModel.AssemblyList?.RefreshSave();
+			}
+		}
 	}
 }