Check B - Envelope Manifest Authority-Field Coverage

Verdict: ENVELOPE_MANIFEST_COVERAGE_NEEDS_FIX

The proposed roster now covers the major authority fields and is materially improved. It is not yet a closed machine-checkable schema.

The live envelope also contains detached_seal_anchor.contract, signature, detached_seal_sha256, and notes, while the roster/exclusion rules do not classify all of them unambiguously as bound authority or explicit non-authority. The phrase “authority-bearing field” leaves semantic discretion to the verifier.

Required fix: define an exact allowed-key schema for every envelope nesting level. Every key must be either included in a specified canonical record or explicitly declared non-authority. Unknown/extra/missing keys fail closed. Bind or explicitly exclude the signature/contract fields without ambiguity. Resolve the circular checkpoint-content anchor before finalizing the roster.