chore(openspec): archive add-shop-coupons

Sync the shop-coupons capability plus the order, frontend-mall, and
frontend-shop-admin requirements into the main specs, and write the capability
Purpose the archive leaves as a placeholder.

Renaming the coupon scenario in the flash-sales and group-buying order deltas
to the exact name now in the main order spec keeps those changes archivable,
since a MODIFIED requirement replaces the whole block.

openspec/changes/add-flash-sales/specs/order/spec.md

@@ -15,7 +15,7 @@
 - **WHEN** checkout contains a SKU with an active eligible flash-sale item
 - **THEN** the order item records the server-calculated flash-sale price and activity identity
 
-#### Scenario: coupon applies to a shop without flash lines
+#### Scenario: coupon applies to one matching shop
 - **WHEN** the customer selects an eligible shop coupon and that shop's generated order has no flash-priced lines
 - **THEN** the order records that coupon and its server-calculated discount
 

openspec/changes/add-group-buying/specs/order/spec.md

@@ -19,7 +19,7 @@
 - **WHEN** the customer selects a coupon for the shop that carries group-buy intent
 - **THEN** checkout returns 409 and creates no orders
 
-#### Scenario: coupon applies to a shop without activity prices
+#### Scenario: coupon applies to one matching shop
 - **WHEN** the customer selects an eligible shop coupon and that shop's generated order has no flash-priced lines and no group-buy intent
 - **THEN** the order records that coupon and its server-calculated discount
 

openspec/changes/archive/2026-09-18-add-shop-coupons/tasks.md

@@ -13,11 +13,11 @@
 
 ## 3. Merchant and customer surfaces
 
-- [ ] 3.1 Add shop-admin coupon-template management and a coupons nav entry scoped to the authenticated shop.
-- [ ] 3.2 Replace mall product-detail coupon strip, buyer coupon list, and checkout coupon selection with shared live-client calls; show persisted discount on payment and order-detail views.
-- [ ] 3.3 Remove the affected direct coupon fixture imports while retaining the complete fixed-data adapter rollback surface.
+- [x] 3.1 Add shop-admin coupon-template management and a coupons nav entry scoped to the authenticated shop.
+- [x] 3.2 Replace mall product-detail coupon strip, buyer coupon list, and checkout coupon selection with shared live-client calls; show persisted discount on payment and order-detail views.
+- [x] 3.3 Remove the affected direct coupon fixture imports while retaining the complete fixed-data adapter rollback surface.
 
 ## 4. Verification and specification
 
-- [ ] 4.1 Seed deterministic coupon templates and verify the live claim-to-checkout-to-cancel flow against the API.
-- [ ] 4.2 Run cargo test for vmall-api, builds for mall and shop-admin, and strict validation for this OpenSpec change.
+- [x] 4.1 Seed deterministic coupon templates and verify the live claim-to-checkout-to-cancel flow against the API.
+- [x] 4.2 Run cargo test for vmall-api, builds for mall and shop-admin, and strict validation for this OpenSpec change.