After a plan/reflection is elaborated and before it executes, three fresh blind
sub-agents (correctness / robustness / simplicity) attack it on the big model;
the main loop RE-THINKS every aspect a BLOCKER lands (a named plan change, or
[deferred]) and re-challenges once if the plan materially changed. Advisory into
each skill's existing human gate — the human stays the decider.
- lib/challenge-plan.md — reusable phase: fail-safe (never fail open),
severity-driven (any single-lens BLOCKER = must-address), RE-THINK loop
- agents/plan-challenger.md — challenger role (read-only, big-model per BDR-066)
- lib/tests/plan-challenger.test.sh — 41-assertion structure lock
- wired into 11 orchestrators: ship-feature/init-project/feat/bugfix (build-plan),
onboard/audit-delta/code-clean (proposals), seo/geo/harden/web-validate (fix-bundle)
Hardened by dogfooding: 3 blind challengers reviewed this feature's own v1 plan
and caught 4 BLOCKERs (fail-open, consensus-buries-lone-finding, wrong model
tier vs BDR-066, false on-disk-plan premise) — all fixed here.
Clearer scoped name for the W3C + WCAG skill. Updated: folder (git mv),
frontmatter name, H1 title, command refs, CLAUDE.md routing, 6 profiles
(functional — activate the skill by folder name), cross-refs in
harden/seo/depth-matrix/client-handover, agent dispatch refs, README +
USAGE tables.
Confidentiality: the client-deliverable leak-guard regex
(client-handover-writer.md) now matches BOTH /web-validate and legacy
/validate, so older client docs stay covered.
Left intentionally: validator-analyzer agent name (lockstep with
subagent_type + registry), .validate-cache/ + VALIDATE.md (audit-file
family {SEO,GEO,HARDEN,CSO,VALIDATE}.md), .claude/ history (append-only),
CHANGELOG old entry (added a new "renamed" entry instead). NL trigger
keywords kept so "validate" still routes here. Third-party html-validate
untouched.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01W9sqAwZxBMZSynZoVrEJhd
Bastien Chanot