The overview's quartile poles and the turn strip's width-quartile labels also mark the
full-span position (the last record / last turn), so the log's end carries its figure like the
quartiles do. The full-span pole insets by its own 1px width (calc(100% - 1px)): at exactly
left 100% the pole falls wholly past the scroller's clip, while the number label keeps reading
leftward inside the pane. The collapsed-at-start pole still drops — at the left edge its
label would clip and the pane edge already answers. Chip tips and the README now say quartiles
and the full span.