Three releases shipped a tarball that crashed on every boot (tls-options/3.8.41,
head-response-guard #7040/#7065) because no gate ever EXECUTED the artifact.
check:pack-boot packs the tree, installs the tarball into a clean prefix
(postinstall runs for real), boots the installed CLI on a reserved port with an
isolated DATA_DIR and polls /api/monitoring/health until it returns 200 with
the packed version — failing loudly with the server's last output otherwise.
Wired into the CI package-artifact job (reuses the dist/ the job already
assembles) and into check:release-green --with-build (parallel slow wave).
Live evidence: packed v3.8.49, installed and booted in 16.6s, health 200.
