chore: add max zoom-in scale limit (1000x)

app/mainwindow.h

@@ -62,6 +62,8 @@ protected:
     QSize sizeHint() const override;
 
 private slots:
+    void on_actionZoomIn_triggered();
+    void on_actionZoomOut_triggered();
     void on_actionCopyPixmap_triggered();
     void on_actionCopyFilePath_triggered();
     void on_actionPaste_triggered();