feat(studio): a phone's header folds into one button, the open ruler no longer rides the photo

docker/frontend/src/App.tsx

@@ -505,12 +505,6 @@ export function Workspace() {
   const [flipH, setFlipH] = useState(() => session.flipH ?? false);
   const [flipV, setFlipV] = useState(() => session.flipV ?? false);
   const [openParam, setOpenParam] = useState<string | null>(null);
-  // A finger on the photo, moving the open ruler. The look it is moving is not
-  // rendered while the hand is down: a develop and a JPEG is the one thing here
-  // that costs more than a frame, and a render landing between two moves of a
-  // drag is the drag the reader feels. The number the finger stops on is applied
-  // when it lifts, and the render follows it then — one for the whole gesture.
-  const [rulerDragging, setRulerDragging] = useState(false);
   // The HSL mixer: which hue band the ruler edits, whether the eyedropper is
   // armed, and the last colour it read off the photo.
   const [hslBand, setHslBand] = useState<HslBandId>('red');
@@ -1054,11 +1048,6 @@ export function Workspace() {
     // recipe, so a preview behind it would only compete for the same renderer —
     // and the user is watching the live one. It comes back with the camera.
     if (!engine || !previewBytes || shooting) return;
-    // A hand on the photo is a drag of the open ruler, and a drag is not a
-    // moment to render: the value it lands on comes with the finger's own lift,
-    // and this effect runs again then (rulerDragging is a dependency) — so one
-    // render for the whole gesture instead of one in the middle of it.
-    if (rulerDragging) return;
     const token = ++renderToken.current;
     const timer = setTimeout(async () => {
       setBusy(t('act.exporting'));
@@ -1118,7 +1107,7 @@ export function Workspace() {
     }, PREVIEW_DEBOUNCE_MS);
     return () => clearTimeout(timer);
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [engine, previewBytes, recipe, preview, frameId, cropEditing, cropLive, cropRect, rotation, straighten, flipH, flipV, useGeotag, gpsInfo, gpsStyle, markOn, markText, markStyle, comparing, shooting, rulerDragging]);
+  }, [engine, previewBytes, recipe, preview, frameId, cropEditing, cropLive, cropRect, rotation, straighten, flipH, flipV, useGeotag, gpsInfo, gpsStyle, markOn, markText, markStyle, comparing, shooting]);
 
   // The source copy behind previewBytes, re-made only when previewMax moves:
   // applying a crop upgrades it, CANCEL/UNDO brings the 1600px one back.
@@ -1455,9 +1444,6 @@ export function Workspace() {
   const sliderEditRef = useRef(false);
   useEffect(() => {
     sliderEditRef.current = false;
-    // A row that is no longer the open one is not being held: whatever gesture
-    // was moving it ended with it.
-    setRulerDragging(false);
   }, [openParam]);
   // The watermark's drag box rides the same one-edit-per-gesture rule as a knob:
   // a whole drag is one undo step, not one per pointer move. The ref clears
@@ -4734,27 +4720,6 @@ export function Workspace() {
           canCompare={!!source}
           onSaveOriginal={() => void saveOriginal()}
           onClear={() => setClearing(true)}
-          // The open ruler, handed to the stage as the track the photo itself
-          // becomes: a chip's ruler stands at the foot of a phone's screen, and
-          // the corner being judged is at the top of it, so a finger dragged
-          // across the picture moves the knob instead. STRAIGHTEN and TONE CURVE
-          // open no row (see `slider`), and neither hands anything over.
-          rulerDrag={
-            slider
-              ? {
-                  value: slider.value,
-                  min: slider.min,
-                  max: slider.max,
-                  step: slider.step,
-                  onChange: slider.onChange,
-                  // The gesture's two edges: while the hand is on the photo the
-                  // look is not rendered, and the number it stops on is the one
-                  // that lands (see `rulerDragging`).
-                  onStart: () => setRulerDragging(true),
-                  onEnd: () => setRulerDragging(false),
-                }
-              : null
-          }
           picking={picking}
           onPickColor={pickColor}
           brushTool={brushTool}