terraform-infra was scoped to NetBox plus Kea DHCP, but Kea is managed by
the kea-operator CRDs in argocd-apps; the two declare the same subnets and
would fight. The repo is narrowed to the NetBox side and renamed to match.
- add the terraform-netbox repository (squash-only, Owners-gated, pre-commit
and plan required)
- remove terraform-infra