CONTRIBUTING.md only covered the contributor flow (add a changeset to
your PR). The maintainer flow — taking accumulated changesets (or a
manual version bump) on dev and turning it into a published npm
artifact — was implicit. That's a problem when a downstream consumer
cites a specific commoners alpha version and expects the release
procedure that produced it to be retraceable.

docs/RELEASE.md covers:
- When to cut a pre-1.0 alpha vs (eventual) post-1.0 stable release
- The linked-package versioning model from .changeset/config.json
  (all linked packages share one version)
- Path A: changeset-driven release (pnpm changeset version + pnpm release)
- Path B: manual bump path that's been used in practice when no
  changesets accumulated, with the caveat that the changelog must be
  filled in by hand
- Verification checklist (npm view, git tag, dist.tarball reachable,
  CHANGELOG entries) before announcing

CONTRIBUTING.md gets a "Releases" section pointing at the new doc so
maintainers can find it without grepping.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>