feat(ui): open editor on double-click for lists and tasks

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/MainWindow.axaml.cs

@@ -1,4 +1,5 @@
 using Avalonia.Controls;
+using Avalonia.Input;
 using ClaudeDo.Ui.ViewModels;
 
 namespace ClaudeDo.Ui.Views;
@@ -16,4 +17,15 @@ public partial class MainWindow : Window
         if (DataContext is MainWindowViewModel vm)
             await vm.InitializeAsync();
     }
+
+    private void OnListItemDoubleTapped(object? sender, TappedEventArgs e)
+    {
+        if (sender is Control c && c.DataContext is ListItemViewModel item
+            && DataContext is MainWindowViewModel vm)
+        {
+            vm.SelectedList = item;
+            if (vm.EditListCommand.CanExecute(null))
+                vm.EditListCommand.Execute(null);
+        }
+    }
 }