Code block copy test

A highlighted TypeScript block (exercises the Shiki path):

import fs = require("fs")

class MyClass {
  public static myValue: string
  constructor(init: string) {
    this.myValue = init
  }
}

A plain block with no language (exercises the lang="text" fallback path):

plain text line one
plain text line two

A block with backslash escapes (PHI-641 regression fixture — these must survive verbatim through escapeSvelte into the rendered page):

const pattern = /\d+\s\\/
const winPath = "C:\\Users\\example"