Show 'Go to App' button for authenticated users on landing page

Instead of displaying sign-in buttons to already authenticated users,
the homepage now detects authentication status and shows a 'Go to App'
button that redirects to the home page.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/[locale]/page.tsx

@@ -1,13 +1,14 @@
 import { FC, ReactNode } from 'react';
 import { Main } from '@/app/ui/Main';
 
-import { authConfig } from "@/app/lib/auth";
+import { authConfig, myAuth } from "@/app/lib/auth";
 import { SignInButton } from '@/app/ui/SignInButton';
 import Image from 'next/image';
-import { getTranslations } from "next-intl/server";
+import { getTranslations, getLocale } from "next-intl/server";
 import isWebview from "is-ua-webview";
-import { headers } from 'next/headers'
+import { headers } from 'next/headers';
 import { ExclamationTriangleIcon } from "@heroicons/react/24/outline";
+import Link from 'next/link';
 
 type Provider = {
   id: string;
@@ -38,6 +39,8 @@ function getKeyValuesFromObject<T>(obj: any, keys: (keyof T)[]): T {
 
 const Page:FC = async () => {
 
+  const session = await myAuth();
+  const locale = await getLocale();
   const providers = await getProviders();
   const t = await getTranslations("login-page");
   // get userAgent from NextJS
@@ -76,11 +79,21 @@ const Page:FC = async () => {
       }
       <span className="flex justify-center">
         {
-          Object.values(providers).map((provider) => (
-            <div key={provider.name}>
-              <SignInButton provider={provider} />
-            </div>
-          ))
+          session ? (
+            <Link
+              href={`/${locale}/home`}
+              className="btn btn-neutral btn-lg"
+            >
+              <Image src="/icon2.png" alt="logo" width={32} height={32} />
+              {t("main-card.go-to-app")}
+            </Link>
+          ) : (
+            Object.values(providers).map((provider) => (
+              <div key={provider.name}>
+                <SignInButton provider={provider} />
+              </div>
+            ))
+          )
         }
       </span>
       <video className="m-auto mt-4" title={t("main-card.video-title")} role="img" data-js-id="hero" loop muted playsInline autoPlay poster={t("main-card.image-url")}>