pub fn check_protocol(
client_protocol: Option<u32>,
) -> Result<(), ProtocolReject>Expand description
Fail-closed, strict-equality protocol assert for a deterministic world’s
join. There is deliberately no 0/missing bypass: an absent version is
a reject, not a pass. This is the load-bearing lesson of the motion field-5
silent-skip incident — never silently accept an unknown/absent field on the
deterministic path.