Verified lead time — the judged record

How far ahead each engine tended to warn, per stratum, with sample sizes and misses included. No key required. Returns STRATA and no aggregate: any headline figure must be derived from trackRecord, and headline carries its own selection basis. When a stratum is below the publishability threshold it is withheld rather than rounded up — headlineWithheldReason and abstentionReason say so explicitly.