Fix email field not populating in RSVP edit form

- Changed email_address mapping from rsvpResponse.data.email_address to rsvpResponse.data.attendee_email
- Database stores email as 'attendee_email' but frontend uses 'email_address'
- This fixes the issue where email field would be blank after changing email address

frontend/src/components/RSVPEditForm.tsx

@@ -82,7 +82,7 @@ const RSVPEditForm: React.FC = () => {
         // Pre-fill the form with existing RSVP data
         setFormData({
           name: rsvpResponse.data.name,
-          email_address: rsvpResponse.data.email_address || '',
+          email_address: rsvpResponse.data.attendee_email || '',
           attending: rsvpResponse.data.attending,
           bringing_guests: rsvpResponse.data.bringing_guests,
           guest_count: rsvpResponse.data.guest_count,