feat: Update login navigation and authentication flow

- Changed navigation from '/editor' to '/tests' after successful login.
- Introduced token state management in AuthContext for better handling of authentication.
- Updated login function to store JWT instead of Google token.
- Added error handling for login and test fetching processes.

style: Enhance UI with new footer and test list styles

- Added a footer component with copyright information.
- Created a new TestList component with improved styling and animations.
- Implemented responsive design for test cards and filter tabs.
- Added loading and error states for better user experience.

fix: Improve API interaction for test fetching and password verification

- Refactored API calls to use a centralized studentApi utility.
- Enhanced error handling for API responses, including unauthorized access.
- Implemented password verification for protected tests before starting them.

Frontend/src/components/Footer.jsx

@@ -0,0 +1,14 @@
+const Footer = () => {
+  return (
+    <footer className="footer-bar fixed bottom-0 left-0 right-0 border-t border-slate-200/40 dark:border-gray-800/20 bg-black">
+      <div className="flex items-center justify-center h-7">
+        <span className="text-xs text-slate-400 dark:text-gray-400 flex items-center">
+          Copyright © 2025. Made with
+          ♡ by Ishika and Arnab.
+        </span>
+      </div>
+    </footer>
+  );
+};
+
+export default Footer;