fix(eks): backoff and terminal state on delete re-drive, CSI volume reclaim reporting, independent e2e subtests (#642)

* fix: bound EKS DELETING re-drive with backoff and a terminal give-up

reapCluster re-drove purgeClusterInfra on every GC tick with no attempt
tracking, so a permanently-failing teardown (e.g. an unretriable
DependencyViolation) was retried forever. Track attempt count and last
attempt time on ClusterMeta, back off exponentially between re-drives,
and give up after maxDeleteReapAttempts with a single error-level log.
Status stays DELETING on give-up so the cluster's infra remains tracked
and billable pending operator intervention, preserving the ADR-0006 §6
billable-before-sweep invariant.

* fix: create the EKS e2e node role independently in each subtest

runEBSCSIVolume string-built the worker node role ARN without ever
creating it, only passing because runIRSAPod's t.Cleanup discarded
DeleteRole's error while the role was still attached to its instance
profile, leaving it behind for EBSCSIVolume to reuse by naming
convention. Extract ensureNodeRole and call it independently from both
subtests, detaching the role from its instance profile before deleting
it and asserting that error instead of discarding it.

* fix: reclaim CSI-provisioned EBS volumes on EKS cluster delete

purgeClusterInfra tore down the control plane, nodegroups, and
networking but never looked at EBS volumes, so any volume the
in-cluster CSI driver had provisioned for a PVC was left behind
untracked and unbilled for. Add a report-only reclaim step that scans
for volumes tagged with the cluster's CSI owner tag and logs them for
operator follow-up.

Volumes are never auto-deleted: a PV's reclaim policy (Delete vs
Retain) is a Kubernetes-side property the CSI driver does not tag onto
the EC2 volume, so there is no safe way to tell from tags alone
whether deleting a given volume is intended. This mirrors the
volume-leak reaper's existing mark-and-alarm policy for the same
reason.

The cluster-owner tag requires the EBS CSI controller's
--k8s-tag-cluster-id flag, added here to the controller manifest;
without it a CSI volume carries no cluster-scoped tag and reclaim
would have to guess across every cluster sharing the account.

* fix: persist the last purge error on a wedged DELETING cluster

DeleteReapExhausted told an operator a cluster's teardown had given
up, but not why: nothing recorded the failing purge's error.
Persist it on every failed re-drive, not only once the reaper
exhausts its attempts, so it is visible on a still-retrying cluster
too. Status stays DELETING throughout, preserving the billing
invariant that untorn-down infra remains tracked.

* fix: make the EKS e2e suite confirm its CSI volume is actually deleted

The EBSCSIVolume subtest deleted its PVC on cleanup but never
confirmed the underlying volume was reclaimed, so a CSI driver that
silently failed to delete it would leak a volume with nobody
noticing. The suite provisions and owns this volume, so unlike
production teardown it can safely wait on its StorageClass's Delete
reclaim policy: capture the CSI volumeHandle while the PVC is bound,
then have cleanup poll EC2 for that exact volume to disappear before
the addon/nodegroup that run the CSI controller are torn down.

scripts/images/eks-node/addons/aws-ebs-csi-driver/1.40.1/10-controller.yaml

@@ -94,6 +94,7 @@ spec:
         - --batching=true
         - --logging-format=text
         - --user-agent-extra=kustomize
+        - --k8s-tag-cluster-id={{CLUSTER_NAME}}
         - --v=2
         env:
         - name: CSI_ENDPOINT