Reference implementation docs

Guides for the Rust reference crate in src/.

Treat SPEC.md as the authoritative source of truth. User-facing docs start at Getting started and Concepts.

Start here

Document	Description
architecture.md	Layers, binding matrix, error model
crate-layout.md	Module map
public-api.md	Library surface notes (implementers)
spec-completeness.md	Chapter coverage matrix
release-runbook.md	Maintainer release checklist
non-goals.md	Explicit out-of-scope items
testing-plan.md	Fixtures and golden strategy

Pipeline (current tools)

parse → COM → validate → analyze → plan → optimize → match → compile → run
                                                              └→ conformance

Consumer API pages: Python · Rust · WASM · Node.