[V5] Mindmap layout, excessive animation error when adding child nodes, and layout cannot be called layout

### Describe the bug / 问题描述

添加节点后调用layout，仅在固定位置绘制出了子节点，未触发过度动画；
再次添加节点并调用layout，第一次添加的节点动画才触发，第二次添加的节点仍添加到了固定的位置；

添加节点后调用render才可以触发动画，但节点的初始位置错误。

预期结果：添加子节点后，调用layout/render，触发expand动画，新增的子节点应从父节点位置开始过渡

### Reproduction link / 重现链接

https://codesandbox.io/p/sandbox/romantic-napier-f96gcs

### Steps to Reproduce the Bug or Issue / 重现步骤

重现链接中写了延时操作

### G6 Version / G6 版本

🆕 5.x

### Operating System / 操作系统

macOS

### Browser / 浏览器

Edge

### Additional context / 补充说明

_No response_

Start with the linked CodeSandbox reproduction and trace the sequence of adding child nodes, then calling layout or render. Compare the animation and initial-position behavior across repeated additions; done means each new child starts at its parent position and transitions with the expand animation.

Written by the indexing model from the issue text.