feat: add page renderer detection tool

[Darley-Wey]

Summary

• add page_getRenderer to report the current renderer as webview or skyline
• include raw wx.getSkylineInfoSync() output for diagnostics
• clarify component selector guidance for bounding client rect lookup

Validation

• npm run build

[Copilot]

Pull request overview

This PR adds a new Page tool to detect the current Mini Program renderer (WebView vs Skyline) and refines the guidance shown to users for cross-component bounding client rect queries.

Changes:

• Add page_getRenderer tool that calls wx.getSkylineInfoSync() and returns the inferred renderer plus raw diagnostics.
• Register the new tool in the Page tools list.
• Update element_getBoundingClientRect description to clarify how selector/innerSelector should be used with custom components.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/tools/page.ts	Adds and registers page_getRenderer renderer-detection tool and outputs diagnostics.
src/tools/element.ts	Updates tool description text to clarify selector behavior across custom components.

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[yfmeii]

感谢贡献！这里我建议调整一下实现方向：不新增 page_getRenderer 工具，而是把渲染器信息合并到现有的 mp_currentPage 返回结果里。

原因有两个：

1. wx.getSkylineInfoSync().isSupported 表示的是“当前运行环境是否支持 Skyline”，不是“当前页面是否正在使用 Skyline 渲染”。在支持 Skyline 的 WebView 页面上，当前实现会误判为 skyline。
2. 渲染器信息本质上属于当前页面信息，放在 mp_currentPage 更合适，也能避免新增工具带来额外上下文占用。

我这边实测到一个反例：

{
  "renderer": "webview",
  "skylineInfo": {
    "isSupported": true,
    "version": "1.4.7"
  }
}

建议改法：

• 移除新增的 page_getRenderer 工具
• 在 mp_currentPage 返回结果中增加：
  • renderer: 当前页面实例的渲染器，例如 webview / skyline
  • skylineInfo: wx.getSkylineInfoSync() 的原始诊断信息

renderer 建议通过当前页面实例读取，而不是从 skylineInfo.isSupported 推断，例如：

const runtimeInfo = await miniProgram.evaluate(() => {
  const pages = getCurrentPages();
  const page = pages[pages.length - 1];

  return {
    renderer: page?.renderer ?? null,
    skylineInfo:
      typeof wx.getSkylineInfoSync === "function"
        ? wx.getSkylineInfoSync()
        : null,
  };
});

这样 mp_currentPage 就能同时告诉调用方当前页面路径、query、尺寸、滚动位置和真实 renderer，也不需要额外增加一个工具。