Scheduled `hermes update --yes` runs on Windows loop against the venv-holder guard when the
Desktop app relaunches its backend, and the refusal text is the only clue. The new read-only
flag runs the same scan (_detect_venv_python_processes, late-bound through hermes_cli.main)
and the same classifiers (pausable-gateway matcher, _hermes_holder_subcommand) and prints
[{pid, exe, argv, kind}], exiting 0 when the venv is free and 3 when holders remain, so
automation can stop exactly those PIDs and retry. Nothing is terminated; the flag is
handled in the update preflight before the lock, backup, or any mutation. Off Windows the
guard never fires and the list is [].
Fixes#117246
eaef5ec717