Macro sh_progress 

macro_rules! sh_progress {
    ($($args:tt)*) => { ... };
}

Prints a progress message to stderr with a trailing newline.

Use for transient progress updates outside the spinner.

Suppressed when:

• --quiet is set, or
• stderr is not a tty (e.g. CI logs, piped consumers).

Always returns Ok(()); progress is best-effort and never fails the caller.