The salvaged restart (#119815) exited 9 when `hermes gateway start --all`
failed, which makes the hand-off's finally block write ok:false, show the
error finale and log "detached update FAILED" in the Desktop even though
the code, venv and Desktop build all verified. Move the restart after the
outcome is settled and surface a restart failure through Write-Result's
existing manual flag instead: the Desktop's boot dialog shows the
`hermes gateway start --all` follow-up, and the update stays a success.
Publish a UI stage so the marquee names the step.
Extend the salvaged test with the exit-code invariant (red on the PR's
own head) and correct the update_cmd_windows docstring that said the
Desktop never restarts the messaging gateway.
Closes#119809
0f1544f903