Function expected_verdict 

pub fn expected_verdict(record: &[u8; 1664], trusted: &VerifyingKey) -> u8

The verdict byte the hardware must write for record, given the trusted Ed25519 key.

Each check runs on the raw bytes, independently of the others, exactly as the hardware does: a bad key index still gets its Merkle and chain checks (with the index’s low 7 bits), and a bad header still gets its certificate checked. Only the combination matters for validity, but the byte pins down every bit, so the card run is checked bit for bit.