feat (login page): add a sign in / log in page

app/finances/layout.tsx

@@ -2,16 +2,21 @@
 
 import { useEffect } from "react";
 import { useRouter } from "next/navigation";
+import { useSession } from "next-auth/react";
 import Sidebar from "@/components/Sidebar";
 
 export default function AuthLayout({ children }: { children: React.ReactNode }) {
+    const { status } = useSession();
     const router = useRouter();
 
     useEffect(() => {
-        if (sessionStorage.getItem("wyview_auth") !== "true") {
+        if (status === "unauthenticated") {
             router.push("/");
         }
-    }, [router]);
+    }, [status, router]);
+
+    if (status === "loading") return null;
+    if (status !== "authenticated") return null;
 
     return (
         <div className="flex min-h-screen">