MEP-56 note 01: Language surface (Ruby target)

Author: research pass for MEP-56 (Mochi to Ruby transpiler). Date: 2026-05-29 (GMT+7).

Mochi language features mapped onto their CRuby 3.2+ lowering obligations: scalars, string ops, collections, Data.define records, tagged Data.define sum types, lambda closures, Thread agents, SizedQueue streams, async with Fiber, CGI/net::http fetch, and LLM cassette replay.

Full research note content for MEP-56 note 01.