Flow: Shopper registers → browses → orders → confirms

A complete customer journey across 4 API calls. Step 1 — Customer registers an account (POST /api/v1/users). Step 2 — Customer browses the product catalogue (GET /api/v1/products). Step 3 — Customer places an order linking their account to a product (POST /api/v1/orders). Step 4 — Customer views order confirmation with full details expanded (GET /api/v1/orders/:id?expand=user,product).