v2.3.19

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: v2.3.18...v2.3.19