CodeHighlighter 支持更灵活的配置

### 需求动机

现在的 `CodeHighlighter` 粗暴地引入了所有语言的支持，导致打包的 js 体积巨大，着实有点浪费。而且诡异的是为啥 `refractor` 和 `highlight.js` 都被打包进去了，按理来说应该是二选一的。

### 提议的 API 是什么样的？

_No response_

Start by inspecting the CodeHighlighter implementation and its current refractor and highlight.js integration; the issue names no source file or test. Trace why all languages are bundled and why both highlighters are included. Done should provide a documented flexible configuration that avoids unnecessary language support and duplicate highlighter bundles.

Written by the indexing model from the issue text.