List a bookable product's selectable resources

Returns the pool of interchangeable resources a PUBLISHED bookable product can be booked on (B3 resource pools, ADR-0038 decision F), scoped to the `:siteId` in the URL and served behind a required storefront publishable key. The list is EXPOSED only when the `reservations_resource_pools` flag is on AND the product's `resource_selection_mode` is `customer_optional`: each entry carries a wire-encoded resource id (`bres_...`) and its merchant-given display name, and NOTHING else (no capacity, tenant, or availability field). In `auto` mode, or with the flag off, the list is EMPTY (resources are not exposed; the buyer never picks one). A missing / draft / archived / cross-tenant product, a non-`bookable` product, and a product with no configured calendar all return an identical 404 (no existence oracle). The returned ids are the exact tokens the buyer echoes back as `resourceId` on the booking write to request a specific resource. > **Note:** This endpoint requires the e-commerce feature to be enabled on your site.