feat(interactive): host task-based ConPTY sessions in Command Center

Adds an 'Open ConPTY session' entry that fetches a task's launch spec and hosts
an embedded ConPTY terminal as a Mission Control pane, coexisting with the
streamed-log monitor panes (streaming stack untouched). Introduces IMissionControlPane
+ ConPtyPaneViewModel, a non-destructive Panes mirror (Monitors prefix + ConPtySessions
suffix) so unrelated monitor churn never tears down a live terminal, and a grid<->tabs
layout toggle. Launch failures surface via the footer error strip.

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

@@ -67,6 +67,12 @@ public partial class TaskRowView : UserControl
             await vm.RunInteractivelyCommand.ExecuteAsync(row);
     }
 
+    private void OnOpenConPtySessionClick(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)
+            vm.OpenConPtySessionCommand.Execute(row);
+    }
+
     private async void OnPickUpInTerminalClick(object? sender, RoutedEventArgs e)
     {
         if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)