Function ripples_at 

pub fn ripples_at(
    clicks: &[ClickEvent],
    frame: Frame,
    ripple_frames: u32,
) -> Vec<(f32, f32, f32)>

Active click ripples at project frame, for the ED.19 overlay.

Each entry is (x, y, age) where age ramps 0.0 (at the click) → 1.0 (at the end of the ripple_frames window); the renderer expands + fades a ring across that age. Clicks outside the window are skipped. Returns empty when ripple_frames == 0. Pure.