The form's 0/1/130 statuses gate both the ISO configurator and first-boot
setup, and nothing tested them. Stubs gum with scripted per-screen answers
and drives each prompt bare under `set -euo pipefail` — the shape that makes
the status capture load-bearing, since a cancelled prompt is a failing
assignment. A RETURN trap marks that the prompt returned its status rather
than the shell dying inside it; both exit identically otherwise, so that
marker is what catches a regression to a plain `status=$?`.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
