feat: restore previous action on Escape from ActionSelect

Pressing Escape from ActionSelect now restores the previous action
(e.g. ActionClone) instead of staying in Select mode. Adds
ConnectEvents() to the Action base class for action resume support.

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

OpenNest/Actions/Action.cs

@@ -15,6 +15,8 @@ namespace OpenNest.Actions
 
         public virtual void OnPlateChanged() { }
 
+        public virtual void ConnectEvents() { }
+
         public abstract void DisconnectEvents();
 
         public abstract void CancelAction();

OpenNest/Controls/PlateView.cs

@@ -25,6 +25,7 @@ namespace OpenNest.Controls
         private string status;
         private Plate plate;
         private Action currentAction;
+        private Action previousAction;
         private List<LayoutPart> parts;
         private Point middleMouseDownPoint;
 
@@ -283,6 +284,8 @@ namespace OpenNest.Controls
                 case Keys.Escape:
                     if (currentAction.IsBusy())
                         currentAction.CancelAction();
+                    else if (currentAction is ActionSelect && previousAction != null)
+                        RestorePreviousAction();
                     else
                         SetAction(typeof(ActionSelect));
                     break;
@@ -650,6 +653,11 @@ namespace OpenNest.Controls
 
             if (currentAction != null)
             {
+                if (type == typeof(ActionSelect) && !(currentAction is ActionSelect))
+                    previousAction = currentAction;
+                else
+                    previousAction = null;
+
                 currentAction.CancelAction();
                 currentAction.DisconnectEvents();
                 currentAction = null;
@@ -664,6 +672,7 @@ namespace OpenNest.Controls
         {
             if (currentAction != null)
             {
+                previousAction = null;
                 currentAction.CancelAction();
                 currentAction.DisconnectEvents();
                 currentAction = null;
@@ -688,6 +697,20 @@ namespace OpenNest.Controls
             Status = GetDisplayName(type);
         }
 
+        private void RestorePreviousAction()
+        {
+            var action = previousAction;
+            previousAction = null;
+
+            currentAction.CancelAction();
+            currentAction.DisconnectEvents();
+
+            action.ConnectEvents();
+            currentAction = action;
+
+            Status = GetDisplayName(action.GetType());
+        }
+
         public void AlignSelected(AlignType alignType)
         {
             if (SelectedParts.Count == 0)