ssp2 — Syncular v2 wire codec (Rust POC)
A fresh implementation of the SSP2 envelope, the SSG2 rows-segment format,
the §2.4 row codec, §8 realtime control messages, and the §11 canonical
JSON debug rendering — built from SPEC.md alone (no reference to
the v1 Rust tree or the v2 TypeScript implementations) to prove the
written protocol contract is language-neutral. Conformance is pinned by
the golden vectors in spec/vectors/.