Add small implementations

SineStriker

2023-12-01 0d31eda795a5bbfd62f070b54f2409761a0eb87f

 src/core/corewindowagent.h

@@ -24,6 +24,7 @@
            Close,
            NumSystemButton,
        };
        Q_ENUM(SystemButton)

    public Q_SLOTS:
        void showSystemMenu(const QPoint &pos);