Function truncate_to_width 

pub fn truncate_to_width(s: &str, max_cols: usize) -> String

Truncate s to at most max_cols visible columns, appending an ellipsis when truncation actually elides content. Skips ANSI SGR escape sequences (\x1b[...m) when counting visible width — they consume characters in the string but no terminal columns. The truncation point is always at a character boundary that’s NOT inside an escape sequence, so we never emit a half-broken \x1b[3 to the terminal.