fix SonarPen for iOS

src/app_layout.cpp

@@ -1012,6 +1012,13 @@ void App::init_menu_tools()
                 popup_exp->destroy();
             };
             
+#if __IOS__
+            popup_exp->find<NodeButtonCustom>("sonarpen")->on_click = [this, popup_exp](Node*) {
+                [ios_app sonarpen_start];
+                popup_exp->mouse_release();
+                popup_exp->destroy();
+            };
+#endif
         };
     }
 }