hermes update decides restart ownership from the live grandchild argv,
not from an env marker. Newly generated plists now include the flag.
The stderr_timestamp wrapper upgrades only historical Hermes gateway
run shapes for stale plists and leaves arbitrary launchd children unmarked.
launchd only stamps XPC_SERVICE_NAME on its direct child. The timestamp
wrapper is that child, so the grandchild gateway sees XPC_SERVICE_NAME=0
and the supervised-conflict guard refuses the service's own spawn.
Forward HERMES_GATEWAY_EXTERNAL_SUPERVISOR=1 when the wrapper itself is
launchd-supervised. Interactive XPC_SERVICE_NAME=0 starts stay unmarked.
Fixes#86893
Teknium