Adds EnrollAttendeesDialog and FinalistEnrollmentCard components and
wires the card above FinalistSlotsCard on the LIVE_FINAL round Overview,
giving admins the missing UI entry point to enroll mentoring-round teams
into the Grand Final via EMAIL or ADMIN_CONFIRM mode.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
