test(desktop): apply the Edit Plate dialog directly in the outline tests

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

OpenNest.WinForms.Tests/Forms/EditPlateFormOutlineTests.cs

@@ -20,7 +20,6 @@ public class EditPlateFormOutlineTests
         using var form = new EditPlateForm(plate);
         var size = (TextBox)form.Controls.Find("textBoxSize", true)[0];
         var clear = (Button)form.Controls.Find("buttonClearOutline", true)[0];
-        var done = (Button)form.Controls.Find("applyButton", true)[0];
         Assert.False(size.ReadOnly);
         Assert.False(clear.Enabled);
 
@@ -30,9 +29,9 @@ public class EditPlateFormOutlineTests
         Assert.True(clear.Enabled);
         Assert.Equal(new Size(48, 96).ToString(), form.SizeString);
         Assert.Contains("6 vertices", ((Label)form.Controls.Find("labelOutline", true)[0]).Text);
-        Assert.True(done.Enabled);
+        Assert.True(((Button)form.Controls.Find("applyButton", true)[0]).Enabled);
 
-        done.PerformClick();
+        form.Apply();
         Assert.Equal(Ell(), plate.Outline);
         Assert.Equal(48, plate.Size.Width);
         Assert.Equal(96, plate.Size.Length);
@@ -46,9 +45,10 @@ public class EditPlateFormOutlineTests
         var size = (TextBox)form.Controls.Find("textBoxSize", true)[0];
         Assert.True(size.ReadOnly);
 
-        ((Button)form.Controls.Find("buttonClearOutline", true)[0]).PerformClick();
+        form.Outline = null; // what Clear does
         Assert.False(size.ReadOnly);
-        ((Button)form.Controls.Find("applyButton", true)[0]).PerformClick();
+        Assert.False(((Button)form.Controls.Find("buttonClearOutline", true)[0]).Enabled);
+        form.Apply();
 
         Assert.Null(plate.Outline);
         Assert.Equal(48, plate.Size.Width);

OpenNest/Forms/EditPlateForm.cs

@@ -186,6 +186,9 @@ namespace OpenNest.Forms
             Outline = plate.Outline;
         }
 
+        /// <summary>Writes the dialog's values to the plate, as Done does.</summary>
+        internal void Apply() => Save();
+
         private void Save()
         {
             // The outline carries its own size; a parsed size would drop it.