quality-playbook v1.2.0: state machine analysis and missing safeguard detection

[andrewstellman]

Add Step 5a (state machine completeness analysis) and expand Step 6 with missing safeguard detection patterns. These catch two categories of bugs that defensive pattern analysis alone misses: unhandled states in lifecycle/status machines, and operations that commit users to expensive work without adequate preview or termination conditions.

Validated against 5 codebases — all known bugs surfaced. README regenerated via npm run build.

[github-actions]

🔍 Skill Validator Results

2 resource(s) checked | ✅ All checks passed

Full output

Found 1 skill(s)
[quality-playbook] 📊 quality-playbook: 9,277 BPE tokens [chars/4: 10,926] (comprehensive ✗), 34 sections, 6 code blocks
[quality-playbook]    ⚠  Skill is 9,277 BPE tokens (chars/4 estimate: 10,926) — "comprehensive" skills hurt performance by 2.9pp on average. Consider splitting into 2–3 focused skills.
�[32m✅ All checks passed (1 skill(s))�[0m

[Copilot]

Pull request overview

Updates the quality-playbook skill to v1.2.0 by adding explicit guidance for state machine completeness analysis and extending risk analysis to include “missing safeguard” detection, improving the playbook’s ability to surface unhandled lifecycle states and costly/irreversible operations without adequate user guardrails.

Changes:

• Bumped quality-playbook metadata/version banner to v1.2.0 and updated its description to mention the new analyses.
• Added Step 5a: Trace State Machines to the core exploration workflow.
• Extended defensive pattern reference material with state machine and missing safeguard patterns; updated the skills index entry accordingly.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
skills/quality-playbook/SKILL.md	Version bump + adds Step 5a state machine tracing and expands Step 6 prompts for missing safeguard detection.
skills/quality-playbook/references/defensive_patterns.md	Adds reference sections for state machine patterns and missing safeguard patterns, plus updates the “Minimum Bar”.
docs/README.skills.md	Updates the skill catalog entry to reflect the expanded capability wording.