v0.4.2

Fixed

• After a rollback, every later install run refused to upgrade — silently. --rollback points devgrail-server:latest back at the displaced build, but versions.env is written before the health gate and so still names the release that was rolled off. The skip-if-unchanged check compared that file against the registry and asked only whether something was tagged :latest, so it concluded "already at vX — skipping" and did nothing: the host kept running the old binary while versions.env, the installer's own closing banner and any script reading them all reported the new one. /healthz was the only thing telling the truth, and disagreeing with it looked like a stale response rather than the symptom it was. The only way forward was to delete versions.env by hand, which nothing documented. The check now asks whether :latest is that version — it compares against the release tag docker load gave those exact bytes — and when it is not, moves the tag back to them rather than re-downloading images that are already on the host. --dry-run reports that state instead of calling it unchanged, and --rollback now says plainly that versions.env names the release it rolled off and that re-running goes forward again.