* feat(resilience): populate dataVersion field from seed-meta timestamp
Sets dataVersion to the ISO date of the most recent static bundle
seed, making the data vintage visible to API consumers.
* fix(resilience): bump score cache to v7 for dataVersion field addition
* feat(resilience): external index correlation validation (ND-GAIN, INFORM)
Batch validation script computing Spearman rho between WorldMonitor
resilience scores and ND-GAIN readiness / INFORM risk indices for 50
representative countries. Identifies top divergences.
Phase 4 gate: rho > 0.6 with at least 2 benchmark indices.
* fix(resilience): use correct score cache key v5 in correlation script
Was hardcoded to v4, but production is v5 after PR #2821 (baseline/stress
engine). Script would miss all cached scores and fail with "Too few
scores available".
* chore(resilience): remove unused redisGetJson from correlation script