feat(F-090): completed feature

work/artifacts/F-090/implementer.md

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+# F-090 — Implementer evidence
+
+## Changes
+
+- `project/src/modules/catalog/api/catalog.routes.ts`
+  - `serializeProduct` now includes `brand` and `expirationDate`, which are already present on the domain/repository product.
+  - This fixes `/catalog/products` responses consumed by the admin listing.
+- `project/apps/admin/src/features/products/components/sections/InventorySection.tsx`
+  - SKU and EAN display/edit controls now use `rows[variant.id].variant`, the state updated after a successful PATCH, instead of the immutable initial `variants` array.
+  - This keeps the newly saved value visible after leaving edit mode and when opening the editor again.
+
+## Validation
+
+- Root `npm run typecheck` → exit 0
+- Admin `npx tsc --noEmit` → exit 0
+- Admin ESLint on `InventorySection.tsx` → exit 0
+- Backend PATCH route remains `/products/:id/variants/:variantId`; no API contract or schema change.