ADMIN

Re-sends the ticket email (with the consolidated PDF) for a completed
fulfillment order to the customer. Intended for server-to-server use by
qup-core — e.g. support requests, a lost email, or a corrected address.

The caller is a cross-campaign admin authorized by the
funtrips/fulfillment.write scope, so the endpoint is not
campaign-scoped: the order is resolved by fulfillment_order_id alone,
and an unknown id returns 404.

By default the ticket is sent to the email stored on the order. Supply
email in the body to override the recipient. A request body is required;
send {} to use the stored recipient.

Only COMPLETED orders that have a generated ticket can be resent —
otherwise 409 Conflict. If no recipient can be resolved, 422.