Compare the HELO/EHLO hostname announced by the sending server (first
Received hop) against the sender IP's PTR records, surfacing the same
signal as x-ptr/policy.ptr in Authentication-Results. Adds helo_hostname
and helo_ptr_match to DNSResults, applies a 15-point PTR sub-score
penalty on mismatch, and displays the result in a new HELO/PTR
Consistency card.
