Function push_window 

pub fn push_window(
    lines: &mut Vec<Line>,
    label: &str,
    w: &UsageWindow,
    theme: &Theme,
    now: DateTime<Utc>,
    elapsed: Option<i32>,
)

Append the standard three-line block every vendor uses for a usage window: icon + label, progress bar + bold percentage, then the dim reset countdown.

elapsed draws the pace marker inside the bar; pass None for a plain bar.