History: handle Tapped at ListBox level to copy output for entire row; switch template back to Grid with ContextMenu; stretch item content for full-row target.

src/AdvancedCalculator/Views/MainView.axaml.cs

@@ -1,7 +1,11 @@
 using System;
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.VisualTree;
 using AdvancedCalculator.ViewModels;
+using AdvancedCalculator.Models;
 
 namespace AdvancedCalculator.Views;
 
@@ -15,6 +19,7 @@ public partial class MainView : UserControl
     }
 
     private MainViewModel? _vm;
+    private ListBox? _historyList;
 
     private void OnAttachedToVisualTree(object? sender, VisualTreeAttachmentEventArgs e)
     {
@@ -23,6 +28,14 @@ public partial class MainView : UserControl
         {
             _vm.CopyRequested += OnCopyRequested;
         }
+
+        _historyList = this.FindControl<ListBox>("HistoryList");
+        if (_historyList is not null)
+        {
+            // Handle taps anywhere in a history row to copy output text
+            _historyList.AddHandler(InputElement.TappedEvent, OnHistoryTapped,
+                RoutingStrategies.Tunnel | RoutingStrategies.Bubble);
+        }
     }
 
     private void OnDetachedFromVisualTree(object? sender, VisualTreeAttachmentEventArgs e)
@@ -31,6 +44,11 @@ public partial class MainView : UserControl
         {
             _vm.CopyRequested -= OnCopyRequested;
         }
+        if (_historyList is not null)
+        {
+            _historyList.RemoveHandler(InputElement.TappedEvent, OnHistoryTapped);
+            _historyList = null;
+        }
         _vm = null;
     }
 
@@ -47,4 +65,21 @@ public partial class MainView : UserControl
             // Ignore clipboard errors; e.g., browser permission or missing gesture context
         }
     }
+
+    private void OnHistoryTapped(object? sender, TappedEventArgs e)
+    {
+        // Find the ListBoxItem the tap originated from
+        var source = e.Source as IVisual;
+        var container = source?.FindAncestorOfType<ListBoxItem>();
+        if (container?.DataContext is not HistoryItem item)
+            return;
+
+        var vm = DataContext as MainViewModel;
+        if (vm?.CopyHistoryOutputCommand.CanExecute(item) == true)
+        {
+            vm.CopyHistoryOutputCommand.Execute(item);
+            // Mark handled to avoid unintended selection change on tap
+            e.Handled = true;
+        }
+    }
 }