Resilience Phase 2: Structural Rebuild

Phase 2 of the Country Resilience Index reference-grade upgrade. Rebuilds the top-level shape from five flat domains into three pillars with partly non-compensatory aggregation, adds recovery capacity pillar, and ships a full validation suite.

Parent plan: docs/internal/country-resilience-upgrade-plan.md

PR Status Tracking

Task	Title	PR	Status
T2.1	Three-pillar schema + schemaVersion v2.0 feature flag	#2977	Completed
T2.2a	Signal tiering registry (Core/Enrichment/Experimental)	#2979	Completed
T2.2b	Recovery capacity pillar (6 dimensions, 5 seeders)	#2987	Completed
T2.3	Three-pillar aggregation with penalized weighted mean	#2990	Completed
T2.4	Cross-index benchmark (INFORM, HDI, WRI vulnerability; ND-GAIN deferred, FSI retired)	#2985	Completed
T2.5	Outcome backtest framework (7 event families; 4 frozen reference sets, 3 live Redis label sets)	#2986	Completed
T2.6/T2.8	Sensitivity suite v2 + ceiling-effect detection	#2991	Completed
T2.7	Railway cron for weekly validation suite	#2988	Completed
T2.9	Language/source-density normalization (informationCognitive)	#2992	Completed
Closeout	Phase 2 scorecard + v2.0 changelog + flag flip	This PR	Completed