Fix: Hide scrollbar on content area (scroll still works)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

studio-v2/app/globals.css

@@ -4,6 +4,15 @@
 
 /* BreakPilot Studio v2 - Base Styles */
 
+/* Hide scrollbars globally but keep scroll functionality */
+.scrollbar-hide::-webkit-scrollbar {
+  display: none;
+}
+.scrollbar-hide {
+  -ms-overflow-style: none;
+  scrollbar-width: none;
+}
+
 * {
   box-sizing: border-box;
   margin: 0;