fix(sidebar): allow vertical scrolling in mobile agent list

Changed from Gesture.Simultaneous() to Gesture.Race() so that vertical
scroll and horizontal swipe-to-close are mutually exclusive based on
initial movement direction.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/app/src/components/sliding-sidebar.tsx

@@ -206,7 +206,10 @@ export function SlidingSidebar({ selectedAgentId }: SlidingSidebarProps) {
       isGesturing.value = false;
     });
 
-  const swipeGesture = Gesture.Simultaneous(
+  // Use Race so that whichever gesture activates first wins - if vertical scroll
+  // happens first (via Native), the Pan gesture fails; if horizontal swipe
+  // happens first, Pan wins and closes the sidebar
+  const swipeGesture = Gesture.Race(
     isOpen ? closeGesture : openGesture,
     Gesture.Native()
   );