[Bug] initial position for tooltip is incorrect in react-vchart

Version

2.0.0

Link to Minimal Reproduction

null

Steps to Reproduce

const getData = () =>
  ['2:00', '4:00', '6:00', '8:00', '10:00', '12:00', '14:00', '16:00', '18:00'].map(time => ({
    time,
    value: Math.random() * 10
  }));

const getSpec = () => ({
  type: 'line',
  data: {
    values: getData()
  },
  xField: 'time',
  yField: 'value'
});

const root = document.getElementById(CONTAINER_ID);
const { VChart } = ReactVChart;
const { useState, useRef, useEffect } = React;

const Card = () => {
  const [spec, setSpec] = useState(getSpec());
  const chartRef = useRef(null);
  useEffect(() => {
    window['vchart'] = chartRef;
  }, []);

  const handleSwitchData = () => {
    setSpec(getSpec());
  };

  return (
    <div>
      <VChart ref={chartRef} spec={spec} tooltipRender={()=>{
        return <div>1111</div>
      }}/>
      <button
        style={{ position: 'absolute', top: 0, left: '50%', transform: 'translate(-50%, 0)' }}
        onClick={handleSwitchData}
      >
        Switch Data
      </button>
    </div>
  );
};

ReactDom.createRoot(root).render(<Card />);

// release react instance, do not copy
window.customRelease = () => {
  ReactDom.unmountComponentAtNode(root);
};

Current Behavior

Tooltip 的初始位置出现在左下角，第一次 hover 时会出现 tooltip 从左下角移动过来的情况。

Expected Behavior

正确计算 Tooltip 初始位置。

Environment

- OS:
- Browser:
- Framework:

Any additional comments?

No response

Reproduce the issue with the provided ReactVChart example, focusing on the chartRef, tooltipRender callback, and Switch Data handler. Trace tooltip positioning during the initial render and after switching data, then verify that the first hover starts at the correct position without visible movement.