login register

app/_layout.tsx

@@ -0,0 +1,27 @@
+import { Stack, router } from "expo-router";
+import { useEffect, useState } from "react";
+import AsyncStorage from "@react-native-async-storage/async-storage";
+
+export default function RootLayout() {
+  const [isLoading, setIsLoading] = useState(true);
+  const [isLoggedIn, setIsLoggedIn] = useState(false);
+
+  useEffect(() => {
+    const checkAuth = async () => {
+      const token = await AsyncStorage.getItem("authToken");
+      setIsLoggedIn(!!token);
+      setIsLoading(false);
+    };
+    checkAuth();
+  }, []);
+
+  if (isLoading) return null;
+
+  return (
+    <Stack>
+      {!isLoggedIn && <Stack.Screen name="index" options={{ title: "Đăng ký / Đăng nhập" }} />}
+      {isLoggedIn && <Stack.Screen name="(tabs)" options={{ headerShown: false }} />}
+    </Stack>
+  );
+  
+}