Points Usage Flow

During checkout, loyalty points can be redeemed:

1. User navigates to checkout (GET /orders/checkout/?page=LoyaltyCardPage)

2. System displays available points and conversion rate

3. User selects amount to redeem (POST with selected_loyalty_amount)

4. System validates points availability

5. Points deducted from total order amount

6. On order creation, external system debits points

7. Failed point redemption blocks order creation