feat(k8s): add the k3s-test-1 worker nodes (#307)

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.

home/hosts/linux/k3s-test-1-master-2.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ../../linux/core.nix ];
+}

home/hosts/linux/k3s-test-1-master-3.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ../../linux/core.nix ];
+}

home/hosts/linux/k3s-test-1-worker-1.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ../../linux/core.nix ];
+}

home/hosts/linux/k3s-test-1-worker-2.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ../../linux/core.nix ];
+}

home/hosts/linux/k3s-test-1-worker-3.nix

@@ -0,0 +1,3 @@
+{
+  imports = [ ../../linux/core.nix ];
+}