Function quorum_state_write_decision 

pub fn quorum_state_write_decision(
    kraft_version: u16,
    leader_epoch: u32,
    has_leader: bool,
    leader_id: u64,
    has_vote: bool,
    voted_id: u64,
    all_voter_ids_fit: bool,
) -> QuorumStateWriteDecision

Reject states that would be clamped, lose an identity, or select an unsupported schema when persisted. The one ensures pins both variants: Accept exactly when fits_signed_json holds.