message: Cell: fix dragging != null
diff: @@ -151,7 +151,7 @@ export const Cell: FC<CellProps> = (props: CellProps) => {
  };
  useEffect(() => {
  - if (dragging != null) {
  + if (dragging !== undefined) {
  const listEl = rootElRef?.current?.closest('.List');
  if (listEl) {
  