feat(ui): keyboard shortcuts (/ Ctrl+N Space Esc)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/Views/Islands/TasksIslandView.axaml.cs

@@ -1,8 +1,17 @@
 using Avalonia.Controls;
+using ClaudeDo.Ui.ViewModels.Islands;
 
 namespace ClaudeDo.Ui.Views.Islands;
 
 public partial class TasksIslandView : UserControl
 {
-    public TasksIslandView() { InitializeComponent(); }
+    public TasksIslandView()
+    {
+        InitializeComponent();
+        DataContextChanged += (_, _) =>
+        {
+            if (DataContext is TasksIslandViewModel vm)
+                vm.FocusAddTaskRequested += (_, _) => AddTaskBox.Focus();
+        };
+    }
 }