观影室增加屏幕共享

src/components/Sidebar.tsx

@@ -63,6 +63,10 @@ const Sidebar = ({ onToggle, activePath = '/' }: SidebarProps) => {
   const pathname = usePathname();
   const searchParams = useSearchParams();
   const watchRoomContext = useWatchRoomContextSafe();
+
+  if (pathname === '/watch-room/screen') {
+    return null;
+  }
   // 若同一次 SPA 会话中已经读取过折叠状态，则直接复用，避免闪烁
   const [isCollapsed, setIsCollapsed] = useState<boolean>(() => {
     if (