## ADDED Requirements

### Requirement: Live shop coupon surfaces
The mall SHALL load a product's currently claimable shop coupons and the signed-in customer's coupon list through the shared API client, replacing direct coupon fixtures. Checkout SHALL present eligible owned coupons separately for each shop order and show the server-returned discount after submission. Payment and order-detail views SHALL show the persisted `discount_minor` and post-discount total from the order payload.

#### Scenario: claim from a product page
- **WHEN** a signed-in shopper claims an active coupon with remaining stock from a product page
- **THEN** it appears in the shopper's coupon list without a fixture import

#### Scenario: select coupon by shop
- **WHEN** a cart spans two shops and the shopper selects a coupon for one shop
- **THEN** checkout submits the choice only for that shop and the other shop remains undiscounted

#### Scenario: order shows realized discount
- **WHEN** checkout succeeds with a coupon on one shop order
- **THEN** that order's payment and detail views show the server discount and reduced total without a client-calculated amount