Function run_embedded 

pub fn run_embedded(program: Vec<OsString>, args: Vec<OsString>) -> ExitCode

run for a host process that is not the rich executable: program is the command that starts this CLI again (for the Python wheel, [sys.executable, "-m", "rs_rich"]), used for --batch workers and the demo’s child --watch, where the binary runs its own executable. An empty program means the current executable, as in run.

A host may call this from several threads at once (the wheel releases the GIL), but a run’s plugins, program and colour settings are process-wide: runs take turns, each whole, so one never clears another’s plugins.