Root cause: submitFormPayment used entity_type 'sa_registrations' which
triggered completeRegistration() on payment — jumping straight to step 4.

Fixes:
- Use entity_type 'sa_registration_form' so only form_payment_status is
  updated (not status/payment_status)
- Remove status='completed' for returning players — they still need photo
  + disciplines steps
- Fix determineStep: only jump to 4 on actual status=completed/assessed,
  not on payment_status=paid
- Lookup API now returns is_existing_player + registration_fee_paid flags
- Wizard badges show "لاعب مسجل بالفعل" and "الاستمارة مدفوعة" indicators
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>