docs(08-08): human sign-off on v1.0-VALIDATION-INDEX.md (NYQ-02/03 complete)

- Flip v1.0-VALIDATION-INDEX.md frontmatter draft -> signed-off (Sébastien QUEROL, 2026-04-13)
- Tick index sign-off line (45/45 pass, 0 fail-fix-v1.1)
- Replicate dated sign-off line into all 7 per-phase VALIDATION.md Validation Sign-Off blocks
- Tick nyquist_compliant checkbox in phases 01/02/03/04/05/07 (06 already ticked)
- Upgrade Approval lines phases 01-05 from 'pending' to signed-off with index back-link
- Tick REQUIREMENTS.md NYQ-02/NYQ-03 and flip Traceability Pending -> Complete
- Phase 4 attestation-only runtime gap recorded in index Residual Risk block (not reopened per plan 10-03 sign-off)

.planning/milestones/v1.0-VALIDATION-INDEX.md

@@ -3,13 +3,15 @@ milestone: v1.0
 type: validation-index
 audit_date: 2026-04-13
 auditor: Sébastien QUEROL
-status: draft
+status: signed-off
+signed_off_by: Sébastien QUEROL
+signed_off_date: 2026-04-13
 ---
 
 # v1.0 Validation Index — Nyquist Rollup
 
 **Audit date:** 2026-04-13
-**Auditor:** Sébastien QUEROL (pending human sign-off)
+**Auditor:** Sébastien QUEROL (signed off 2026-04-13)
 **Compiled by:** Claude (gsd-executor, plan 08-08)
 
 **Tally:** 45/45 pass, 0 deferred-v1.2, 0 fail-fix-v1.1, 0 wont-do
@@ -119,4 +121,4 @@ Phase 4 rows 1–5 (SCRPT-01..05) carry attestation-only runtime proof via RTVAL
 
 ## Sign-Off
 
-- [ ] Nyquist audit complete — 2026-04-13 — Sébastien QUEROL
+- [x] Nyquist audit complete — 2026-04-13 — Sébastien QUEROL