HSL: click a colour chip to open its panel, the way PICK does

The colour band chips only aimed the mixer before; now they open the same
panel the eyedropper opens, seeded with the colour the chip is named after
(hexToRgb turns that readout back into the RGB bytes the picker stores).
A pick already on the photo keeps its spot — only a mixer with nowhere to
hang takes the middle of the frame.

The HSL column itself is untouched: 8 chips, the rule, IMAGE,
HUE/SAT/LUM, the readout and RESET all stay where they were.

docker/frontend/src/Library.tsx

@@ -684,7 +684,7 @@ export function Library() {
                     title={t('lib.subsHint')}
                     onClick={() => setDeep((prev) => !prev)}
                   >
-                    {t(deep ? 'lib.subsHide' : 'lib.subsShow')}
+                    <span className="chip-label">{t(deep ? 'lib.subsHide' : 'lib.subsShow')}</span>
                   </button>
                 </>
               ) : null}