Build a custom DtC checkout with the Vinoshipper order APIs

Steps

1. Call POST /api/v3/p/orders/estimate-shipping with the ship-to address and product/quantity list to retrieve available carrier rates (e.g. UPS Ground, 2nd Day Air) and let the customer choose one.
2. Call POST /api/v3/p/orders/estimate-taxes with the same products plus the chosen shippingRate to get a tax/fee breakdown, using the response's `extraFeesTotal`, `taxesTotalWithoutFees`, and `taxesTotal` fields for display.
3. Call POST /api/v3/p/orders with customer info (including date of birth for age verification), shipToAddress, products, the selected shippingRate, and the `fees`/`taxes` values from the estimate step to create the order.
4. To charge a card directly, first create the order without `paid: true` (it will be PENDING), call the Create SetupIntent API for a Stripe `clientSecret`/`publishableKey`, confirm the card with Stripe.js, then call POST /api/v3/p/orders/{orderNumber}/purchase with the resulting `stripePaymentMethodId`.
5. Check the response for `status: SUCCESS` and `isCompliant: true` to confirm the order was created and passed compliance.
6. On failure, branch on error type: HTTP 400 validation errors (fix the request), HTTP 200 with `isCompliant:false` and an `orderProblems` array (compliance violation — the order can still be updated via the Update Order API), or HTTP 5xx server errors (retrying can help for transient issues, and log the `vs-trace-id` response header for support).