006-distribution

Distribution: npm binary shim + the release pipeline

How the spec-spine CLI reaches users who do not have a Rust toolchain. Two channels already existed but were unspecced: the tag-gated GitHub release pipeline (release.yml) that builds the five per-triple archives, and install.sh (curl | sh) that consumes them. This spec adopts both as governed territory and adds a third channel: an npm binary-distribution shim under npm/ so a TS/JS repo can `npm i -D spec-spine` and get the CLI with no Rust. The shim is a launcher, not a native addon: the main package's bin resolves a per-triple platform package (optionalDependencies, os/cpu-gated) and exec's the prebuilt binary, forwarding argv and exit code. No postinstall, no network at install, no archive extraction; it works under `npm ci --ignore-scripts` and offline. Version-locked to the binary release tag (npm 0.1.0 ships the v0.1.0 assets).