refactor(gallery): extract controls R16, R18-R24 into GW builders

Entry keypad, thumb-slide pair, waveform region editor, drum roller, LED program row, three-position slide, spun knob, and stomp switch. The drum roller's per-instance clip paths get a uid() helper so two instances can coexist; the region editor's screen-family chips now reach the widget through the card handle (card.gw.el) instead of a stage id, and probe-fams drives its post-recolor check through the handle's set(). Behavioral pass now 78 checks; both probes green.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests/gallery-probes/probe-fams.mjs b/tests/gallery-probes/probe-fams.mjs
index 76759b6..63f9dc3 100644
--- a/tests/gallery-probes/probe-fams.mjs
+++ b/tests/gallery-probes/probe-fams.mjs
@@ -41,10 +41,10 @@ await evl(`document.querySelector('.scope').closest('.card').querySelector('.fc[
 const tr1 = await evl(`getComputedStyle(document.querySelector('.scope polyline')).stroke`);
 ok('N11 amber chip recolors trace', tr0 !== tr1 && tr1 === 'rgb(255, 190, 84)', `${tr0} -> ${tr1}`);
 
-// R19: drag still works after family switch (click vfd, then check setWregion writes var-based fills)
-await evl(`document.querySelector('#wregion').closest('.card').querySelector('.fc[title="vfd"]').click()`);
-await evl(`setWregion(30,70)`);
-const barFill = await evl(`(()=>{const b=document.querySelectorAll('#wregion rect')[10];return b.getAttribute('fill');})()`);
+// R19: drag still works after family switch (click vfd, then check the handle's set() writes var-based fills)
+await evl(`document.querySelector('#card-R19 .fc[title="vfd"]').click()`);
+await evl(`document.getElementById('card-R19').gw.set(30,70)`);
+const barFill = await evl(`(()=>{const b=document.querySelectorAll('#card-R19 svg rect')[10];return b.getAttribute('fill');})()`);
 ok('R19 dynamic fills use vars', barFill.startsWith('var(--scr-'), barFill);
 
 // R17: face gradient stop resolves to amber face after chip