Implement logout functionality for account page

- Create LogoutButton client component using signOut from next-auth/react
- Update account page to use LogoutButton instead of static link
- Convert account page to async server component for proper i18n
- Add locale-aware routing for settings link
- Add logging-out-message translations (EN/HR)

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

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

app/[locale]/account/LogoutButton.tsx

@@ -0,0 +1,20 @@
+"use client";
+
+import { FC } from 'react';
+import LogoutIcon from "@mui/icons-material/Logout";
+import { signOut } from 'next-auth/react';
+import { useLocale, useTranslations } from 'next-intl';
+import { Button } from '@/app/ui/button';
+
+export const LogoutButton: FC = () => {
+    const t = useTranslations('account-page');
+    const locale = useLocale();
+
+    const handleLogout = () => {
+        signOut({ callbackUrl: `/${locale}/login` });
+    };
+
+    return (
+        <Button className='btn' onClick={handleLogout}><LogoutIcon /> {t('logout-button')}</Button>
+    )
+}