Developer TODO Checklist:

• Fetch events from the calendar database or external APIs (e.g. Google Calendar, Zoom Events).
• Setup registration: Connect the "Register" button to a checkout form (Stripe for paid, custom register API for free).
• Save registrations: Store registrants' Okta sub/userID in database to show registration status (e.g. 'You are registered!').
• Implement filtering: Sort by "All Events", "My Registered Events", "Past Events".