Port Rob Loach's ChaiScript.js work (https://github.com/RobLoach/ChaiScript.js)
into the main repository as an Emscripten build target. Adds a GitHub Actions
workflow that builds ChaiScript to WebAssembly and publishes artifacts (JS, WASM,
HTML) for embedding in the official ChaiScript.com website. Includes an HTML
interactive playground frontend and a native test validating the eval API surface.
Co-Authored-By: Rob Loach <robloach@gmail.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
