Block closed event registrations

[trista-chen-29]

Problem

• Users could navigate to the registration page for closed events
• UI did not clearly indicate that registration was unavailable

Changes

• Added closed-event handling in registration page:
  • Show a “Registration Closed” screen when event.status === closed
  • Prevent form from rendering/submitting
• Disabled registration interaction:
  • Button shows “Registration Closed”
  • No requests are sent from frontend
• Connected registration page to real SCEvents API

Verification

• Closed event → blocked registration page

- Calendar popup → “Registration closed” state

[steeevin88]

looks fine to me 😄

[adarshm11]

another trista W