Add OnDetachedFrom method to ContextActionBehavior

Implement OnDetachedFrom to clear ContextFlyout when detached
from a View, ensuring no lingering context menus remain.

Author: pictos

src/PJ.ContextActions.Maui/Controls/ContextActionBehavior.windows.cs

@@ -15,6 +15,11 @@ protected override void OnAttachedTo(View bindable, FrameworkElement platformVie
 		platformView.ContextFlyout = CreateMenu(bindable);
 	}
 
+	protected override void OnDetachedFrom(View bindable, FrameworkElement platformView)
+	{
+		platformView.ContextFlyout = null;
+	}
+
 	WMenuFlyout CreateMenu(View view)
 	{
 		var contextMenu = new WMenuFlyout();