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/TaskListView.axaml.cs

@@ -1,4 +1,6 @@
 using Avalonia.Controls;
+using Avalonia.Input;
+using ClaudeDo.Ui.ViewModels;
 
 namespace ClaudeDo.Ui.Views;
 
@@ -8,4 +10,15 @@ public partial class TaskListView : UserControl
     {
         InitializeComponent();
     }
+
+    private void OnTaskItemDoubleTapped(object? sender, TappedEventArgs e)
+    {
+        if (sender is Control c && c.DataContext is TaskItemViewModel item
+            && DataContext is TaskListViewModel vm)
+        {
+            vm.SelectedTask = item;
+            if (vm.EditTaskCommand.CanExecute(null))
+                vm.EditTaskCommand.Execute(null);
+        }
+    }
 }