Auditor independiente v4 (Conv 3 — Review+Merge, post pm-redesign 2026-05 Punto 4 + story-closure-gate 2026-05-18). Toma story state=developed (AUTO-HANDOFF /dev-team default; manual opt-in via defer_audit:true) → transition state=developed→reviewing → spawna auditor-{be,fe,agentic} según surface. Phase D NEW: gherkin verification matrix (cada scenario 01-spec.md → test path → status, escribe 06-audit/gherkin-matrix.md). Veredicto: APPROVED | CHANGES_REQUESTED | ESCALATED. Self-fix triviales (lint/typo/format) cap 2 iter. Diseño/security/arch → escala. Cuando todos tickets audit-passed, escribe CHECKPOINTS.md (C1-C5 grid: Code | Spec | Architecture | Cross-cutting | Trace) + AUTO-HANDOFF /pm-{brand} merge. Activa cuando user dice: '/auditor', 'audita story', 'revisa tickets', 'verdict', 'review final', 'CHECKPOINTS'.