Add new registrants to event calendar attendee list

You miss attendee additions when registrations aren't mirrored to your calendar, leaving hosts unprepared and invites incomplete. Keep rosters current so hosts have accurate guest lists same day.

Overview

When registrants aren't copied to the calendar, hosts miss invites and logistics slip; this flow ensures every new attendee is appended to the event entry so hosts see accurate guest lists. That means better prep and fewer last‑minute surprises, with rosters updated within minutes.