Maturity badge intensity tuner

Tune the brightness of the maturity SYMBOL badge. Brightness = each (Daily·Weekly·Monthly) combo's position in our 2pc (fixed) confidence-weighted ranking - the same ranking behind the re-rank ★ (#1 brightest, last dimmest; nothing re-scored). Note (#1619): the live badge ★ is now SERVER-ADAPTIVE (current 2pc rank when robust, else the fixed Xpc rank); this tuner visualises a frozen 2pc-fixed snapshot purely to tune the brightness curve, which #1619 leaves unchanged. Drag the sliders to tune the brightness curve; the table re-lights live. A freebie from hoiboy.uk.