bastion/k3s: bootstrap new clusters with cluster-pool IPAM

Every cluster this bastion builds was pinned to ipam=kubernetes, which makes it
permanently single-stack: Cilium reads node.spec.podCIDRs, the controller-manager
writes that once at node join and never revises it, so adding IPv6 later fails
with `required IPv6 PodCIDR not available` and needs a rebuild.

cluster-pool puts allocation in the CiliumNode CRD, where the operator can add
an address family to a running node. Proven in labsim (842408c). It is also
Cilium's own default -- ipam=kubernetes was the deviation.

Pool matches the k3s cluster-cidr (10.42.0.0/16, /24 per node), so a node gets
the same CIDR shape it would have had. IPv4-only for now: the IPv6 pool wants an
apiserver carrying an IPv6 service CIDR, which is a separate change.

Mirrors @michal/cilium-values ciliumBaseValues (cilium-values@11ee509), which
these paths track but do not import.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH

bastion/src/modules/modules/k3s/src/install.ts

@@ -215,7 +215,9 @@ echo "  Using network device: \$DEFAULT_DEV"
 
 KUBECONFIG=/etc/rancher/k3s/k3s.yaml cilium install \\
   --set kubeProxyReplacement=true \\
-  --set ipam.mode=kubernetes \\
+  --set ipam.mode=cluster-pool \\
+  --set ipam.operator.clusterPoolIPv4PodCIDRList='{10.42.0.0/16}' \\
+  --set ipam.operator.clusterPoolIPv4MaskSize=24 \\
   --set devices="\$DEFAULT_DEV" \\
   --set nodePort.directRoutingDevice="\$DEFAULT_DEV"
 

bastion/src/modules/modules/k3s/src/operations/cilium.ts

@@ -47,7 +47,9 @@ export const installCilium: Operation = async (ctx): Promise<OperationResult> =>
   const installResult = await ctx.ssh.exec(
     `KUBECONFIG=/etc/rancher/k3s/k3s.yaml cilium install \
       --set kubeProxyReplacement=true \
-      --set ipam.mode=kubernetes \
+      --set ipam.mode=cluster-pool \
+      --set ipam.operator.clusterPoolIPv4PodCIDRList='{10.42.0.0/16}' \
+      --set ipam.operator.clusterPoolIPv4MaskSize=24 \
       --set k8sServiceHost=127.0.0.1 \
       --set k8sServicePort=6444 \
       --set cni.exclusive=false \