Always enforce fail-closed verification of frozen provenance

Always treat governance inputs as untrusted: verify exact frozen pins before opening paths, then hash and parse one immutable bounded snapshot per regular file. Reject TOCTOU substitutions, aliases, duplicate or malformed JSON/ZIP entries, non-finite values, FIFOs, and resource-limit violations; malformed input must never preserve or create an open output. Chose machine-verifiable external provenance over locally repeated constants and manifests because coordinated code/bundle edits can change both without authenticating the claimed GitHub origin.