feat: add i18n support and add Chinese (#372)

* feat: add i18n support and add Chinese

* fix: resolve conflicts

* Update en.json with cancle settings

* Update zh.json with settngs cancle

---------

Co-authored-by: johnny0120 <15564476+johnny0120@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
Co-authored-by: Willem Jiang <143703838+willem-bd@users.noreply.github.com>

web/src/app/page.tsx

@@ -1,6 +1,7 @@
 // Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 // SPDX-License-Identifier: MIT
 
+import { useTranslations } from 'next-intl';
 import { useMemo } from "react";
 
 import { SiteHeader } from "./chat/components/site-header";
@@ -27,20 +28,20 @@ export default function HomePage() {
     </div>
   );
 }
-
 function Footer() {
+  const t = useTranslations('footer');
   const year = useMemo(() => new Date().getFullYear(), []);
   return (
     <footer className="container mt-32 flex flex-col items-center justify-center">
       <hr className="from-border/0 via-border/70 to-border/0 m-0 h-px w-full border-none bg-gradient-to-r" />
       <div className="text-muted-foreground container flex h-20 flex-col items-center justify-center text-sm">
         <p className="text-center font-serif text-lg md:text-xl">
-          &quot;Originated from Open Source, give back to Open Source.&quot;
+          &quot;{t('quote')}&quot;
         </p>
       </div>
       <div className="text-muted-foreground container mb-8 flex flex-col items-center justify-center text-xs">
-        <p>Licensed under MIT License</p>
-        <p>&copy; {year} DeerFlow</p>
+        <p>{t('license')}</p>
+        <p>&copy; {year} {t('copyright')}</p>
       </div>
     </footer>
   );