How to hide routes while using Chanfana?

The docs say "Just don't use Chanfana, register the route directly":
https://chanfana.pages.dev/examples-and-recipes#hiding-routes-in-openapi-schema
but what if I want docs for dev runs but then hide certain routes in prod?

Is there a way to hide routes from the openapi output?

Start with the linked “hiding routes in OpenAPI schema” documentation and trace how routes are registered and included in the generated OpenAPI output. Done means establishing a supported way to keep documentation routes available during development while excluding selected routes from the production OpenAPI output.

Written by the indexing model from the issue text.