fix(capture): Zoom/Pan vs Rotate gesture modes; drop dead ↻ overlay

Pinch/drag were applying zoom and tilt together on Measure. Add an
explicit Zoom/Pan | Rotate segmented toggle (default Zoom/Pan). Stage
gestures are exclusive per mode; tilt/zoom sliders stay available.

Remove the bottom-center ↻ handle that sat on tick B (hitTick won, so
the icon looked live but only moved the tick).

frontend/src/capture/MeasurePanel.svelte

@@ -37,6 +37,8 @@
   let speciesLoadErr = '';
 
   let cropFill = getCropFill();
+  /** Exclusive stage gestures: Zoom/Pan (default) vs Rotate. Sliders stay available either way. */
+  let gestureMode: 'zoompan' | 'rotate' = 'zoompan';
   $: maskW = state.source.widthPx > 0 ? state.source.widthPx : 0;
   $: maskH = maskW > 0 ? state.approvedMask.bitset.length / maskW : 0;
   $: tape = state.axis.tape;
@@ -200,12 +202,39 @@
     <p class="hint">Orient the slab on the fixed tape line, then enter length, thickness, and species.</p>
     <p class="nudge">The black line is <b>fixed</b>: tilting, dragging and zooming the slab never move it. It stays in the middle of the rectangle.</p>
 
+    <div class="mode-toggle" role="group" aria-label="Stage gesture mode">
+      <button
+        type="button"
+        class="mode-btn"
+        class:active={gestureMode === 'zoompan'}
+        aria-pressed={gestureMode === 'zoompan'}
+        data-testid="gesture-mode-zoompan"
+        on:click={() => (gestureMode = 'zoompan')}
+      >Zoom / Pan</button>
+      <button
+        type="button"
+        class="mode-btn"
+        class:active={gestureMode === 'rotate'}
+        aria-pressed={gestureMode === 'rotate'}
+        data-testid="gesture-mode-rotate"
+        on:click={() => (gestureMode = 'rotate')}
+      >Rotate</button>
+    </div>
+    <p class="nudge mode-hint">
+      {#if gestureMode === 'zoompan'}
+        Pinch to zoom and drag to pan. Rotation gestures are ignored — switch to Rotate or use the tilt slider.
+      {:else}
+        Two-finger twist to rotate (or use the tilt slider). Pan and pinch-zoom are ignored in this mode.
+      {/if}
+    </p>
+
     {#if maskedPreview}
       <PhotoStage
         mode="tape"
         blob={maskedPreview}
         {tape}
         {cropFill}
+        {gestureMode}
         onTapeChange={onTapeChange}
       />
     {:else}
@@ -227,7 +256,7 @@
           <button type="button" class="thumb" aria-label="Tilt right" on:click={() => nudgeTilt(1)}>+</button>
           <span class="val">{tiltShown}°</span>
         </div>
-        <p class="nudge">±90° · ← → tilt 1° · Shift+← → 0.1° · two-finger twist · or drag the ↻ handle</p>
+        <p class="nudge">±90° · slider always works · in Rotate mode: ← → tilt 1° · Shift+← → 0.1° · two-finger twist</p>
       </div>
 
       <div>
@@ -408,6 +437,17 @@
   .panel { padding: 16px; color: #eee; }
   h1 { font-size: 1.3rem; margin: 0 0 8px; }
   .hint { color: #aaa; font-size: 0.9rem; margin: 0 0 8px; }
+  .mode-toggle {
+    display: flex; gap: 0; margin: 10px 0 4px;
+    border: 1px solid #444; border-radius: 10px; overflow: hidden; width: fit-content; max-width: 100%;
+  }
+  .mode-btn {
+    min-height: 44px; padding: 10px 18px; font-size: 0.95rem; font-weight: 600;
+    border: 0; background: #1d1d1d; color: #aaa; cursor: pointer;
+  }
+  .mode-btn + .mode-btn { border-left: 1px solid #444; }
+  .mode-btn.active { background: #00e5ff; color: #002; }
+  .mode-hint { margin: 0 0 10px; }
   .nudge { color: #e8a; font-size: 0.74rem; margin: 6px 0 0; line-height: 1.45; }
   .preview-loading { min-height: 420px; border: 1px solid #333; border-radius: 8px; display: flex; align-items: center; justify-content: center; color: #999; text-align: center; padding: 16px; box-sizing: border-box; }
   .controls { margin-top: 16px; display: flex; flex-direction: column; gap: 14px; }