feat(ui): drag a task into Mission Control to queue it

src/ClaudeDo.Ui/Views/MissionControl/MissionControlView.axaml.cs

@@ -5,6 +5,7 @@ using Avalonia.Interactivity;
 using Avalonia.VisualTree;
 using ClaudeDo.Ui.ViewModels;
 using ClaudeDo.Ui.ViewModels.Islands;
+using ClaudeDo.Ui.Views.Islands;
 
 namespace ClaudeDo.Ui.Views.MissionControl;
 
@@ -23,15 +24,28 @@ public partial class MissionControlView : UserControl
 
     private void OnPaneDragOver(object? sender, DragEventArgs e)
     {
-        e.DragEffects = (e.DataTransfer?.Contains(PaneFormat) ?? false)
-            ? DragDropEffects.Move
-            : DragDropEffects.None;
+        var dt = e.DataTransfer;
+        var accept = (dt?.Contains(PaneFormat) ?? false)
+                     || (dt?.Contains(TasksIslandView.TaskRowFormat) ?? false);
+        e.DragEffects = accept ? DragDropEffects.Move : DragDropEffects.None;
     }
 
     private void OnPaneDrop(object? sender, DragEventArgs e)
     {
         if (DataContext is not MissionControlViewModel vm) return;
-        var draggedId = e.DataTransfer?.TryGetValue(PaneFormat);
+        var dt = e.DataTransfer;
+        if (dt is null) return;
+
+        // A task dragged from the main app → queue it.
+        var taskId = dt.TryGetValue(TasksIslandView.TaskRowFormat);
+        if (!string.IsNullOrEmpty(taskId))
+        {
+            _ = vm.EnqueueTaskAsync(taskId);
+            return;
+        }
+
+        // A pane dragged within the grid → reorder.
+        var draggedId = dt.TryGetValue(PaneFormat);
         if (string.IsNullOrEmpty(draggedId)) return;
         if (e.Source is not Avalonia.Visual src) return;