COI Verification: an unread policy date is never reported missing

COI Verification: a policy date the reading left empty without saying it could not read the cell was reported as missing from the certificate, which turned an illegible expiration date into a coverage deficiency (seen on 1 of 3 live calls on the same certificate, 2026-09-15). A policy date missing from a coverage row the certificate shows is now withheld as not established from the certificate, and a requirement that depends on it returns cannot_determine . Blank limits and unmarked checkboxes are still reported as absent.