event_registration_partner_unique
Ensure each partner can only appear once in the attendee list of any event that enables duplicate protection.
Key Features
- event.event: Adds a Forbid Duplicates option on events so organizers can explicitly require unique attendee partners.
- event.registration: Validates every registration against the event's Forbid Duplicates setting and blocks saving duplicate partners while listing them in the error message.
- event.event: Refuses to activate the Forbid Duplicates setting if duplicate attendees already exist, forcing organizers to clean up conflicts first.