Bug: Header tab for H5/Taro in docs site missing active highlight state

### NutUI 包名

@nutui/nutui

### NutUI 版本号

4.3.15

### 平台

h5

### 重现链接

Start docs site locally by pnpm dev. Click H5 / Taro tab on site header, page content changes normally, but tab active highlight not updated. No online demo link.

### 重现步骤

1. Clone the nutui main branch repository, run `pnpm install` and `pnpm dev` to launch the documentation site locally.
2. Locate the H5 / Taro tab switcher in the top header of docs page.
3. Click to switch between H5 and Taro tab.
4. Observe the tab label highlight status.

### 期望的结果是什么？

When clicking the H5 / Taro tab item, the selected tab should show active highlight style synchronously.

### 实际的结果是什么？

After clicking the tab, page content switches correctly, but the tab label does not update its active highlight state.

### 环境信息

_No response_

### 其他补充信息

This bug belongs to the documentation site page instead of the component library source code.
I have found the root cause and will submit a PR to fix this issue.

Start the documentation site with pnpm install and pnpm dev, then inspect the H5/Taro tab switcher in the top header. Reproduce the tab switch and trace how the selected tab and page content are updated. Done means the selected tab's active highlight changes synchronously with the displayed content.

Written by the indexing model from the issue text.