docs: architecture, guidelines, domain designs, progressive code index

docs/code_index/marketing.md

@@ -0,0 +1,25 @@
+# Index: Marketing (coupons, flash sales, group buying, points)
+
+Domain design: `docs/domains/marketing.md`. Specs: `openspec/specs/shop-coupons/`,
+`flash-sales/`, `group-buying/`, `points-mall/`.
+
+## Backend (`apps/api`)
+
+| Module | Holds |
+|---|---|
+| `modules/coupon/` | template CRUD, claim, checkout discount + redemption |
+| `modules/flash_sale/` | sessions/items CRUD, activity price resolution, reserved stock |
+| `modules/group_buying/` | activities, groups, seat claim at payment |
+| `modules/points/` | points catalog, redemption, fulfillment |
+
+Migrations: `0011_shop_coupons.sql`, `0012_points_mall.sql`,
+`0013_flash_sales.sql`, `0014_group_buying.sql`.
+Tests: `tests/coupons.rs`, `tests/flash_sales.rs`, `tests/group_buying.rs`,
+`tests/points.rs`.
+
+## Frontends
+
+- Mall: `pages/seckill.vue`, `pages/collective.vue`, `pages/integral.vue`,
+  `pages/user/coupons.vue`; checkout coupon selection in `pages/checkout/index.vue`
+- Shop-admin: `pages/coupons.vue`, `pages/flash-sales.vue`, `pages/group-buying.vue`
+- Admin: `pages/points-products.vue`, `pages/points-orders.vue`