gateway.restart already answers "was this gateway launched by a generated
service" (HERMES_SUPERVISED_CHILD or launchd's XPC_SERVICE_NAME, so a plist
that predates the marker still counts); the hint reuses it instead of a
second env read. The negative branch (plain unreachable host without a
supervisor) is now an unmarked test so the Linux lane keeps covering the
function; the macOS-only test holds the positive branch.
7b660e66ee