feat: enhance security by implementing HttpOnly refresh tokens and in-memory access token management

- Added isomorphic-dompurify for improved XSS protection
- Refactored token storage to use in-memory management for access tokens
- Implemented server-side route handlers for OAuth token management
- Introduced security headers in next.config.js
- Removed client-side exposure of client_secret and sensitive tokens
- Updated API interceptors to handle token refresh logic
- Cleaned up cookie management for refresh tokens

app/component/ModalLogout.js

@@ -8,8 +8,13 @@ import { useState } from "react";
 function ModalLogout({ open, handleClose }) {
   const router = useRouter();
   const [loading, setLoading] = useState(false);
-  const logout = () => {
+  const logout = async () => {
     setLoading(true);
+    try {
+      await fetch("/api/auth/logout", { method: "POST" });
+    } catch {
+      // clearing client state below is what matters
+    }
     removeToken();
     router.replace("/login");
   };