Squid 1.8.8 — Versioned blue-green Tentacle upgrades - Versioned install layout: versions/<v> selected by a stable `current` pointer (#402, #403) - Blue-green upgrade on both OSes: the running version is never touched; rollback is an instant pointer flip (#403) - Real-OS upgrade E2E — Linux systemd (#404), Windows SCM + junction (#405) - Version GC (keep newest N, default 3) + same-version re-upgrade no-op (#406)