feat(login): add back-to-home navigation link

[rittika03]

🚀 Feature: Add "Back to Home" Navigation to Login Page

Closes: #113

📝 Description

Currently, the "Access Vault" (Login) page lacks a clear exit path for unauthenticated users, which can lead to higher bounce rates. This PR introduces a "Back to Home" navigation link to improve the User Experience (UX) and provide a seamless way for users to return to the landing page.

🛠 Changes Made

• Navigation Logic: Integrated the Link component from react-router-dom (or next/link) to handle client-side routing to /.
• UI Enhancement: Added a "← Back to Home" link in the top-left section of the login card, ensuring it is distinct from the "Sign Up" action.

✅ Checklist

• My code follows the project's style guidelines.
• I have performed a self-review of my code.
• The link correctly redirects to the root directory (/).
• The UI is responsive and looks good on mobile devices.
• No console errors or warnings are triggered by these changes.