Transport.run

run(argv => [...], stdin => $octets, timeout => $seconds, max_output => $bytes, cancel_fh => $handle) returns a LibTmux::CommandResult. Stdout/stderr are separate octet strings. Nonzero exits are results; spawn, timeout, cancellation, output limits, and supervision failures throw LibTmux::X exceptions. timeout bounds one command's execution loop, excluding supervisor setup, async queue waiting, and separate cleanup time.