v0.16.0 — Requirement-quality rules for specifications

Improvements

• Hold specification statements to a requirement-quality reference (skills/draft-spec/references/requirement-quality.md), adapted from the requirement characteristics in ISO/IEC/IEEE 29148 and written as veriloop's own text so Codex and Claude Code apply the same rules.
• Give every acceptance criterion a permanent AC-<n> identifier that is never renumbered or reused, and state one observable outcome per criterion. Run records and the PRD.md verification chapter cite criteria by identifier.
• Replace words that leave a threshold open ("fast", "etc.", "if possible", "improved") with a bound, a complete set, or a reference behavior; a replacement that needs an unsettled value goes back to the user as a decision.
• Add a non-functional lens (performance and cost bounds, permissions, reliability under failure) to decision-surface enumeration, applied only where the work touches it.
• Add a third guess-hunt question: contradictions between sections, and criteria that join outcomes or leave their threshold open in a way that would let two readers build or judge different behavior.
• Criterion priority is not part of this release.

Verification

• Contract suite passes with four new draft-spec instruction contracts; removing any of the guarded sentences fails the suite.
• evals/test_archive_run.py, evals/test_review_report.py, and evals/test_worker_result_cli.py pass unchanged.

Full Changelog: v0.15.0...v0.16.0