Function is_reagent_trusted_signing_key 

pub fn is_reagent_trusted_signing_key(key_id: &str) -> bool

The one key_id whose matching private key is believed secret today. reagent-v1-dev stays registered in reagent_public_key (so verify_reagent_jekt still checks its signatures), but its private half is documented above as exposed since it was generated, so a signature under it proves nothing about the sender. Receivers record a reagent signature as verified only through verify_trusted_reagent_jekt, which requires this key; any other key yields reagent_verified = Some(false) — an active verification failure, forced sensitive.