- VerifySpec: add SuccessCodes, FailureCodes, RateLimitCodes, MetadataPaths, Body - Preserve legacy ValidStatus/InvalidStatus for backward compat - Add EffectiveSuccessCodes/FailureCodes/RateLimitCodes fallback helpers - Add ExtractMetadata helper using gjson (skeleton for Plan 05-03) - Finding: add Verified, VerifyStatus, VerifyHTTPCode, VerifyMetadata, VerifyError - Add github.com/tidwall/gjson v1.18.0 as direct dependency