Returns true when the AdCP release that bundleKey identifies declares the
top-level adcp_version envelope field. The field landed in AdCP 3.1 per
spec PR adcontextprotocol/adcp#3493 — 3.0 (any patch / prerelease) does
not carry it; 3.1+ does. Used to gate dual-emit on the wire so a 3.0-pinned
client doesn't emit a field its target schema doesn't define.
Returns true when the AdCP release that
bundleKeyidentifies declares the top-leveladcp_versionenvelope field. The field landed in AdCP 3.1 per spec PRadcontextprotocol/adcp#3493— 3.0 (any patch / prerelease) does not carry it; 3.1+ does. Used to gate dual-emit on the wire so a 3.0-pinned client doesn't emit a field its target schema doesn't define.