Accept being the authorized signer

The member a request names accepts, from their own session, and submits the identity details Stable Sea must verify for a new authorized signer: citizenship, date of birth, a US Social Security Number or a passport (a United States citizen gives an SSN; anyone else says whether they have a US SSN), and an address. The name comes from the member's record. Only that member can accept; the request then waits for a compliance operator, who reads the details with the SSN or passport number masked and can reveal the whole value, on the record. The details are sealed on the request and are never returned to the business: not to its admins and not in this answer. A body that does not match this schema (a missing field, a wrong type, a value over its length cap) is refused as invalid_field; a detail the schema accepts and the rules refuse (an ITIN, a date of birth that is not a real day or makes the signer younger than 18, a field the identifier class does not allow) is refused as signer_change_invalid. Neither refusal repeats a submitted value.