v3.20.0 — recoverability skill for developer-safety

MINOR — developer-safety 0.3.0: new recoverability skill.

The autonomy doctrine that governs every phase command (/work, /bugfix, /release) now ships as a standing skill active in every session — not only inside a named phase.

Added

• recoverability skill — the stop-gate is reversibility, not destructiveness or blast-radius. Three-class action table:
  • Recoverable (git push, gh pr create, gh release create, …) → announce + proceed, no confirmation wait
  • Unrecoverable (force-push rewriting shared history, sole-ref branch delete, published-tag overwrite, immutable deploy) → stop + confirm
  • Unresolved decision → stop + ask + log as design/plan gap
• Covers close-out autonomy (archiving completed plans, progress.md appends, ROADMAP moves — always autonomous).
• Documents the carve-outs the doctrine does not relax: worker-tree authority, PII hook, commit authorship.
• Cross-references kill-switch / steer / commit-on-stop as the runtime enforcement layer (the skill is pre-action judgment; the hooks are in-flight controls).