ArgoCD diffs against live state where k8s defaults these fields in:
- parentRefs: group=gateway.networking.k8s.io, kind=Gateway
- backendRefs: group="", kind=Service, weight=1
Matches the pattern from #153 (certificateRefs).
Add port 80 HTTP listener and redirect HTTPRoute to artifactapi,
cattle-system (rancher), litellm, paperclip, and puppetboard — restoring
the redirect behaviour that existed on the previous nginx/traefik Ingress
resources.
Reviewed-on: #145
## Summary
- Replace `Ingress` (nginx) with `Gateway` + `HTTPRoute` using `traefik-internal` GatewayClass
- TLS terminated at the Gateway listener; cert-manager provisions the certificate via `vault-issuer`
- external-dns annotations moved to the Gateway
## Test plan
- [ ] ArgoCD syncs the cattle-system app cleanly
- [ ] cert-manager issues the `rancher-tls` certificate
- [ ] external-dns creates the DNS record
- [ ] `https://rancher.k8s.syd1.au.unkin.net` is reachable
Reviewed-on: #132
unkinben