feat: add single player mode

packages/lib/client-only/hooks/use-is-mounted.ts

@@ -0,0 +1,11 @@
+import { useEffect, useState } from 'react';
+
+export const useIsMounted = () => {
+  const [isMounted, setIsMounted] = useState(false);
+
+  useEffect(() => {
+    setIsMounted(true);
+  }, []);
+
+  return isMounted;
+};