Update NXT demographics from event registrants

For GiveCampus integrations and API.

Export event registrant/attendee contact fields and reconcile changed emails/phones against verified CRM constituent IDs before an authorized CRM import. The event participant export is not a guarantee that every new contact value overwrites NXT constituent demographics. Confirm any enhanced connector options and field rules with the integration owner; do not merge people or overwrite preferred contacts solely by a shared email.