feat(ADM-018): completed feature

work/artifacts/F-009/documenter.md

@@ -0,0 +1,19 @@
+# Documenter — F-009 Brands module
+
+done -> work/artifacts/F-009/documenter.md
+
+## Documentation updated
+- `project/README.md`
+
+## Covered
+- Brand-specific error code `BRAND_SLUG_EXISTS`.
+- Product brand assignment error code `PRODUCT_BRAND_NOT_FOUND`.
+- Brands module endpoint table.
+- Public slug URL rule: `/marca/<slug>`.
+- Product brand filter: `GET /products/search?brandSlug=<slug>`.
+- Catalog product `brand_id` assignment and module-boundary note.
+- Layout entry for `src/modules/brands`.
+
+## Verification
+- `cd project && npm run lint` — PASS after README Prettier normalization.
+- `./scripts/verify.sh` — PASS from repository root before documentation close.