Add worker-1 (4 vCPU / 16 GiB) on shoryu, and worker-2 (4 vCPU / 16 GiB) plus worker-3 (2 vCPU / 8 GiB) on shushou, as microVMs. They come with a genK3sAgentModule and the per-host/output/home-manager wiring, and are labelled node-role.kubernetes.io/worker=true. The masters keep their control-plane:NoSchedule taint, so workloads land on the workers.
Drop the now-meaningless kubevirt- prefix and move the hosts out of
hosts/k8s/, following the existing 12kingdoms-shoukei layout: the
directory and output carry the theme prefix while the configuration,
hostname and colmena target are the bare name (shoryu, shushou, youko).
- hosts/k8s/kubevirt-* -> hosts/12kingdoms-*; the shared disko config
becomes host-disko-fs.nix; the now-different relative imports are fixed
- outputs, vars/networking.nix keys, the Justfile recipes/tags, the eval
tests and the docs follow
- colmena reaches these hosts by IP (a new targetHost override), since
their DNS name changes with the hostname and is not resolvable until
the router learns it