A test- and dev-only escape hatch that builds a RegistryUrl from a plain-HTTP loopback URL, so the integration suites can dial an in-process http://127.0.0.1 server rather than standing up TLS.

This module is exposed only under the dev-http-egress Cabal flag (default off). The release library and the shipped executable are built with the flag off, so this module is not compiled into them and the loopback constructor does not exist in a release artifact: the https-only egress posture cannot be relaxed in production. The production builder is the https-only Ecluse.Core.Security.Egress.mkRegistryUrl.