fix(help): let F1 set a placed part instead of opening help

The Help menu's F1 shortcut took the key before the plate view, so F1
in Clone/Add Part opened help rather than setting the part in place as
it always has. Actions can now claim F1; Clone does, and MainForm lets
the key through to the plate view while it is active.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest.WinForms.Tests/Controls/ActionCloneTests.cs

@@ -60,4 +60,21 @@ public class ActionCloneTests
         Assert.Empty(plate.Parts);
         Assert.True(Assert.Single(view.SelectedParts).IsSelected);
     }, TimeSpan.FromMinutes(1), "The STA test did not complete.");
+
+    [Fact]
+    public void F1SetsThePartInPlaceInsteadOfOpeningHelp() => StaTestThread.Run(() =>
+    {
+        var plate = new Plate(48, 96);
+        using var view = new PlateView { Plate = plate, Size = new System.Drawing.Size(600, 600) };
+        view.ZoomToFit();
+        view.SetAction(typeof(ActionClone), Square("new"));
+
+        Assert.True(view.ActionHandlesF1);
+        Raise(view, "OnKeyDown", new KeyEventArgs(Keys.F1));
+
+        Assert.Single(plate.Parts);
+
+        view.SetAction(typeof(ActionSelect));
+        Assert.False(view.ActionHandlesF1);
+    }, TimeSpan.FromMinutes(1), "The STA test did not complete.");
 }

OpenNest/Actions/Action.cs

@@ -39,6 +39,9 @@ namespace OpenNest.Actions
         /// <summary>The help topic F1 opens while this action is active, or null for the general help.</summary>
         public virtual string HelpTopic => null;
 
+        /// <summary>Whether the action uses F1 itself, so F1 reaches the plate view instead of opening help.</summary>
+        public virtual bool HandlesF1 => false;
+
         public virtual void OnPlateChanged() { }
 
         public virtual void ConnectEvents() { }

OpenNest/Actions/ActionClone.cs

@@ -110,6 +110,9 @@ namespace OpenNest.Actions
 
         public override bool SurvivesPlateChange => true;
 
+        // F1 sets the part in place, as it always has; help stays on the Help menu.
+        public override bool HandlesF1 => true;
+
         public override void OnPlateChanged() => SelectPreviews();
 
         public override void ConnectEvents()

OpenNest/Controls/PlateView.cs

@@ -883,6 +883,9 @@ namespace OpenNest.Controls
         /// <summary>The help topic for the current action, or null when it has none.</summary>
         public string ActionHelpTopic => actionManager.CurrentAction?.HelpTopic;
 
+        /// <summary>Whether the current action takes F1 for itself instead of help.</summary>
+        public bool ActionHandlesF1 => actionManager.CurrentAction?.HandlesF1 == true;
+
         public void AlignSelected(AlignType alignType) => selection.AlignSelected(alignType);
 
         public void AlignSelected(AlignType alignType, LayoutPart fixedPart) =>

OpenNest/Forms/MainForm.cs

@@ -99,6 +99,10 @@ namespace OpenNest.Forms
             }
             if (ProcessUndoKeys(keyData))
                 return true;
+            // A tool that uses F1 itself (Clone sets the part) gets it before help: skip the
+            // Help menu shortcut so the key reaches the plate view.
+            if (keyData == Keys.F1 && activeForm?.PlateView?.ActionHandlesF1 == true)
+                return false;
             // F1 opens the active tool's topic before the Help menu's general help.
             if (keyData == Keys.F1 && activeForm?.PlateView?.ActionHelpTopic is { } topic)
             {