Registration Flow

Standard Registration (with SMS verification):

1. User submits registration data (POST without code)

2. System sends SMS verification code

3. Code stored in session as confirmation_data

4. User resubmits with code parameter

5. System validates phone and code match

6. Creates loyalty account in external system

7. Creates local LoyaltyCard record

8. Sets user attributes: has_loyalty=true, verified_user=true

9. Optionally syncs user data if is_sync=true

OTP Registration (without SMS verification):

1. User already verified via other means

2. Direct submission to /add_loyalty_card_otp/

3. Skips SMS verification entirely

4. Creates loyalty account and local record

5. Sets has_loyalty=true attribute

Search and Link:

1. User submits phone/email to /search_exists_create/

2. System queries external loyalty system

3. If account exists, creates local LoyaltyCard link

4. If not found, returns message (no account creation)