The configurator now peeks into the offline mirror's runtime package for
omarchy-oem-setup before offering the OEM install mode, so an ISO built
against a pre-OEM runtime can't start an install doomed to fail at the
staging phase (which still hard-checks as the backstop). Blank disks with no
OEM choice to offer skip the mode picker entirely, like the pre-OEM flow.
Also keep the test harness QMP socket in /tmp — unix socket paths cap at
~108 bytes, which nested test-run directories can exceed.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>