fix(simulator): prevent crosshair from activating during wire segment editing on mobile

- Add data-segment-handle attribute to segment handle circles in WireLayer
- Skip long-press aiming timer when touch targets segment handle
- Add safety checks to cancel pending timer when segment drag starts
- Ensure segment drag always takes priority over crosshair activation

This fixes the bug where accidentally holding still while dragging a wire
segment would activate the crosshair overlay and interrupt the editing workflow.

frontend/src/components/simulator/SimulatorCanvas.tsx

@@ -402,6 +402,9 @@ export const SimulatorCanvas = () => {
       // Any phase that uses aiming: cancel previous timer first
       if (wireAimingTimerRef.current) { clearTimeout(wireAimingTimerRef.current); wireAimingTimerRef.current = null; }
 
+      // Check if touch is on a segment handle - if so, skip aiming timer (handle drag takes priority)
+      const isOnSegmentHandle = target?.closest('[data-segment-handle]');
+
       const aimPhase = wireAimingPhaseRef.current;
 
       // Already in an aiming phase (aiming_start or aiming_end) → touch updates crosshair immediately
@@ -415,16 +418,21 @@ export const SimulatorCanvas = () => {
 
       // wire_started → long press to aim for endpoint, short drag = pan
       if (aimPhase === 'wire_started') {
-        wireAimingTimerRef.current = setTimeout(() => {
-          wireAimingPhaseRef.current = 'aiming_end';
-          setWireAiming(true);
-          if (navigator.vibrate) navigator.vibrate(30);
-          const world = toWorld(currentTouchRef.current.x, currentTouchRef.current.y);
-          const aimX = world.x;
-          const aimY = world.y + AIMING_OFFSET_Y;
-          setAimPosition({ x: aimX, y: aimY });
-          useSimulatorStore.getState().updateWireInProgress(aimX, aimY);
-        }, AIMING_LONG_PRESS_MS);
+        // Only start aiming timer if NOT on a segment handle
+        if (!isOnSegmentHandle) {
+          wireAimingTimerRef.current = setTimeout(() => {
+            // Double-check: only activate if segment drag hasn't started
+            if (segmentDragRef.current) return;
+            wireAimingPhaseRef.current = 'aiming_end';
+            setWireAiming(true);
+            if (navigator.vibrate) navigator.vibrate(30);
+            const world = toWorld(currentTouchRef.current.x, currentTouchRef.current.y);
+            const aimX = world.x;
+            const aimY = world.y + AIMING_OFFSET_Y;
+            setAimPosition({ x: aimX, y: aimY });
+            useSimulatorStore.getState().updateWireInProgress(aimX, aimY);
+          }, AIMING_LONG_PRESS_MS);
+        }
 
         isPanningRef.current = true;
         panStartRef.current = {
@@ -479,8 +487,10 @@ export const SimulatorCanvas = () => {
         }
       } else {
         // ── 6. Empty canvas → start pan + long press starts aiming (idle phase only) ──
-        if (aimPhase === 'idle') {
+        if (aimPhase === 'idle' && !isOnSegmentHandle) {
           wireAimingTimerRef.current = setTimeout(() => {
+            // Double-check: only activate if segment drag hasn't started
+            if (segmentDragRef.current) return;
             wireAimingPhaseRef.current = 'aiming_start';
             setWireAiming(true);
             if (navigator.vibrate) navigator.vibrate(30);
@@ -538,6 +548,11 @@ export const SimulatorCanvas = () => {
 
       // ── Segment drag (wire editing) via touch ──
       if (segmentDragRef.current) {
+        // Cancel any pending aiming timer - segment drag takes priority
+        if (wireAimingTimerRef.current) {
+          clearTimeout(wireAimingTimerRef.current);
+          wireAimingTimerRef.current = null;
+        }
         const world = toWorld(touch.clientX, touch.clientY);
         const sd = segmentDragRef.current;
         sd.isDragging = true;

frontend/src/components/simulator/WireLayer.tsx

@@ -84,6 +84,7 @@ export const WireLayer: React.FC<WireLayerProps> = ({
             stroke="#007acc"
             strokeWidth={sw}
             style={{ pointerEvents: 'all', cursor: handle.axis === 'horizontal' ? 'ns-resize' : 'ew-resize', touchAction: 'none' }}
+            data-segment-handle={handle.segIndex}
             onMouseDown={(e) => onHandleMouseDown(e, handle.segIndex)}
             onTouchStart={(e) => onHandleTouchStart?.(e, handle.segIndex)}
           />