Function remote_shell_command 

pub fn remote_shell_command(
    config: &WorkerConfig,
    command: &str,
) -> RemoteShellCommand

Prepare a POSIX script without exposing its contents to Windows cmd.exe. Windows uses a fixed sh -s reader, which replaces itself with a command shell whose stdin is empty. An exact sh -s keeps its existing EOF behavior. POSIX workers receive the original command argument and null stdin.