feat: support i18n [skip ci]

web/src/routes/__root.tsx

@@ -1,3 +1,4 @@
+import { LanguageSwitcher } from "@/components/language-switcher";
 import { ModeToggle } from "@/components/mode-toggle.tsx";
 import { ThemeProvider } from "@/components/theme-provider.tsx";
 import { Button } from "@/components/ui/button.tsx";
@@ -17,6 +18,7 @@ function RootComponent() {
               <h2 className="text-lg font-semibold">MemShellParty - JavaWeb</h2>
             </div>
             <div className="flex gap-1 mr-4">
+              <LanguageSwitcher />
               <Button
                 variant="ghost"
                 size="icon"