v2.3.20

Added

• Clusters page (/clusters, under Infrastructure in the nav) lists Kubernetes clusters
  separately from hosts — a k8s-cluster system no longer clutters Infrastructure → All.
• Per-group overlay on the Cluster charts — with no group focused, CPU/memory draw one
  line per namespace / workload / label (top 16 by usage, like the fleet host overlay);
  hover a line for its name, click a table row to focus a single group.
• Namespace scope selector on the Cluster page. Workloads are namespace-qualified so
  deployments that share a name across namespaces stay distinct (rows carry their namespace,
  and drill-down filters by namespace + workload).

Fixed

• Cluster charts no longer stretch a sparse or empty series across the whole panel — the
  x-axis now spans the selected time window (like the host charts).

Fixed

• Re-enrolling a host no longer creates duplicate rows. Systems were keyed by
  (key_id, hostname), so re-adding a cluster/host with a freshly-minted enrollment key
  (the "Add system" flow mints one each time) registered every node again as a NEW row and
  left the old ones behind as offline ghosts. Systems are now identified by
  (workspace_id, hostname) — a re-enroll updates the existing row and its owning key
  follows the latest report. Migration config/0028 collapses existing duplicates (keeps
  the most-recently-seen row per host).

Full Changelog: v2.3.19...v2.3.20