Display attendee counts on event cards

[maernest04]

PR for #2098

Problem

Event cards did not show how many people were going, even though event platforms like Luma and Facebook Events commonly display a {number} going count.

This depends on backend support from SCE-Development/SCEvents#95.

Solution

• Added attendance summary fetching from SCEvents.
• Rendered attendee count in the event card metadata section.
• Displayed the count as {number} people going.
• Kept attendance visibility aligned with the current admin-only backend behavior.
• Updated event date/time formatting to be more readable.

Files Changed

• Clark/src/APIFunctions/SCEvents.js
• Clark/src/Pages/Events/Events.js
• Clark/src/Pages/Events/EventsRegistation.js

Other Changes Made

Event Registration Now Submits To SCEvents

The event registration page previously showed a success message without creating a SCEvents registration.

Solution: added registerForSCEvent and wired the registration form to POST /events/:id/register.

Registration Success Message Is Stricter

Clark could show success even when SCEvents had not completed the registration.

Solution: only treat 201 Created from SCEvents as a completed registration.

Event Date And Time Are Easier To Read

Event cards previously displayed raw date/time values.

Solution: format dates as month/day/year text and times in 12-hour AM/PM format.

Possible Follow-Up Issues

• Update Clark once SCEvents supports public attendee counts for all users, if the backend visibility changes from admin-only.
• Add frontend tests for attendance count rendering and registration submission.

Screenshots

Member view

Admin view

[steeevin88]

can you rebase + add screenshots

[steeevin88]

thanks for adding the screenshot!