/spec-write <feature-id> <title>
Register a spec file in the manifest, validate its structure, and update
indexes. This is the mechanical registration step — run it after
/spec-author has produced the hardened spec content, or when registering
a prerequisite stub.
For authoring hardened specs with adversarial review, use /spec-author
first, then /spec-write to register the output.
Canonical frontmatter schema: .spec/_refs/frontmatter.md is the single
authoritative reference for
[Description truncada. Veja o README completo no GitHub.]