Use project .fwlayout files for Avalonia persistence

Src/Common/FwAvalonia/Detail/DetailModel.cs

@@ -1604,24 +1604,26 @@ public DetailField(
 		public int ObjectHvo { get; }
 
 		/// <summary>
-		/// The class of the compiled view definition this row was projected from (advanced-entry-view):
-		/// the entry's own fields carry "LexEntry"; a row from a descended object (a sense, an
-		/// allomorph)
-		/// carries that object's layout class. Paired with <see cref="LayoutName"/> it keys the per-project
-		/// <c>ViewDefinitionOverride</c> store so the per-field gear-menu commands (Field
-		/// Visibility / Move
-		/// Field) target the right layout. Set by the composer at compose time (null on rows built outside
-		/// the full-entry composer, e.g. the first-slice fallback).
+		/// The class of the compiled view definition this row was projected from. The entry's own
+		/// fields carry "LexEntry"; a row from a descended object carries that object's layout
+		/// class.
+		/// Paired with <see cref="LayoutName"/>, it identifies the exact legacy layout command
+		/// target.
+		/// Set by the composer at compose time; null on rows built outside the full-entry
+		/// composer.
 		/// </summary>
 		public string ClassName { get; set; }
 
 		/// <summary>
-		/// The layout name of the compiled view definition this row was projected from (e.g.
-		/// "Normal").
-		/// See <see cref="ClassName"/>.
+		/// The layout name of the compiled view definition this row was projected from, such as
+		/// "Normal". See <see cref="ClassName"/>.
 		/// </summary>
 		public string LayoutName { get; set; }
 
+		/// <summary>The owning caller part's structural address in the effective legacy
+		/// layout.</summary>
+		public string SourceCallerPath { get; set; }
+
 		/// <summary>
 		/// The project's available CHARACTER-type style names
 		/// the per-WS editor offers when restyling a selection (sourced by the composer from the project's

Src/Common/FwAvalonia/Detail/LexiconFirstSlice.cs

@@ -179,7 +179,8 @@ private static ViewNode StampProductLeaf(ViewNode source, string automationId, s
 			=> new ViewNode(source.StableId, ViewNodeKind.Field, labelOverride ?? source.Label, source.Abbreviation,
 				source.Field, source.RawEditor, source.EditorClassification, source.WritingSystem, source.Visibility,
 				source.Expansion, source.Indented, source.TargetLayout, null,
-				source.LocalizationKey, automationId, HostRouting.Product);
+				source.LocalizationKey, automationId, HostRouting.Product,
+				sourceCallerPath: source.SourceCallerPath);
 
 		private static ViewNode Leaf(string stableId, string label, string field, string editor, string ws, string automationId)
 			=> new ViewNode(stableId, ViewNodeKind.Field, label, null, field, editor,

Src/Common/FwAvalonia/FwAvaloniaTests/DetailRenderingTests.cs

@@ -0,0 +1,68 @@
+// Copyright (c) 2026 SIL International
+// This software is licensed under the LGPL, version 2.1 or later
+// (http://www.gnu.org/licenses/lgpl-2.1.html)
+
+using System.Collections.Generic;
+using System.Linq;
+using Avalonia.Automation;
+using Avalonia.Controls;
+using Avalonia.Headless.NUnit;
+using Avalonia.Threading;
+using Avalonia.VisualTree;
+using NUnit.Framework;
+using SIL.FieldWorks.Common.FwAvalonia.Detail;
+using SIL.FieldWorks.Common.FwAvalonia.ViewDefinition;
+
+namespace FwAvaloniaTests
+{
+	[TestFixture]
+	public class DetailRenderingTests
+	{
+		private static DetailField TextField(string id, string label)
+			=> new DetailField(id, label, label, null, DetailFieldKind.Text,
+				EditorClassification.Known, id, null, HostRouting.Inherit,
+				new List<DetailWsValue> { new DetailWsValue("en", "value") },
+				null, null, isEditable: true, indent: 0, objectHvo: 1234);
+
+		private static DataTree Render(params DetailField[] fields)
+		{
+			var model = new DetailModel("LexEntry", "Normal", fields.ToList(),
+				new List<ViewDiagnostic>());
+			var view = new DataTree(model, null, null, null, null, null);
+			var window = new Window { Content = view, Width = 480, Height = 360 };
+			window.Show();
+			Dispatcher.UIThread.RunJobs();
+			return view;
+		}
+
+		private static List<string> RenderedLabelIds(DataTree view)
+			=> view.GetVisualDescendants().OfType<TextBlock>()
+				.Select(t => AutomationProperties.GetAutomationId(t))
+				.Where(id => !string.IsNullOrEmpty(id) && id.EndsWith(".Label"))
+				.ToList();
+
+		[AvaloniaTest]
+		public void DetailView_RendersOnlyTheRowsInTheModel()
+		{
+			var view = Render(TextField("a", "Alpha"), TextField("c", "Gamma"));
+
+			var labels = RenderedLabelIds(view);
+			Assert.That(labels, Has.Member("a.Label"));
+			Assert.That(labels, Has.Member("c.Label"));
+			Assert.That(labels, Has.No.Member("b.Label"),
+				"a row omitted from the model does not render");
+		}
+
+		[AvaloniaTest]
+		public void DetailView_RendersRowsInModelOrder_SoAReorderIsVisible()
+		{
+			var view = Render(TextField("c", "Gamma"), TextField("a", "Alpha"),
+				TextField("b", "Beta"));
+
+			var order = RenderedLabelIds(view);
+			Assert.That(order.IndexOf("c.Label"), Is.LessThan(order.IndexOf("a.Label")));
+			Assert.That(order.IndexOf("a.Label"), Is.LessThan(order.IndexOf("b.Label")),
+				"rows render in model order");
+		}
+	}
+}

Src/Common/FwAvalonia/FwAvaloniaTests/LayoutChoiceResolutionTests.cs

@@ -93,8 +93,6 @@ public void SelectLayoutForChoice_EmptyOrNullVariants_ReturnsNull()
 			Assert.That(LayoutSourceLoader.SelectLayoutForChoice(null, GuidA), Is.Null);
 		}
 
-		// Two different choiceGuids on the SAME class must yield two DISTINCT
-		// layouts (the selector is the cache-discriminator; the composer keys CompiledModels by choiceGuid).
 		[Test]
 		public void TwoChoiceGuids_OnSameKey_SelectDistinctLayouts_NoCollision()
 		{