[Frontend] — ENHANCEMENT: Add Join Event Modal Component

[Olowodarey]

Modal component for joining a creator event using an invite code. Can be triggered from event detail page or from a shared invite link.

Required Features

1. Invite Code Input:

   • 8-character input field (auto-uppercase, alphanumeric only)
   • Real-time validation
   • "Paste" button to paste from clipboard
   • Auto-fill if code is in URL query param

2. Event Preview (after valid code entered):

   • Event title
   • Creator address
   • Number of matches
   • Current participants / max
   • "Join Event" button

3. Join Flow:

   • Check if user already joined
   • Check if event is full
   • Check if event is active
   • Submit transaction to contract
   • Show success message with redirect to event page

4. Error Handling:

   • Invalid invite code
   • Event full
   • Event cancelled
   • Already joined
   • Transaction failures

Files to create:

• frontend/src/component/creator-events/JoinEventModal.tsx