Traefik matches hosts exactly, so an app serving a wildcard domain under the `traefik` ingress class had a valid certificate but silently 404d on every request. Wildcard domains now render as a `HostRegexp` rule that matches a single label, the same semantics as a Kubernetes wildcard host, so both ingress classes behave the same. Those routes carry an explicit low priority so an exact domain on any app still wins over another app's wildcard, mirroring ingress-nginx.
Domains cannot be reused across ingress objects, and port maps are a function of a domain, so the inversion here makes most sense (at the cost of some downtime when migrating.
