Implement User Authentication System using Firebase

Description
Implement a secure user authentication system using Firebase Authentication to allow users to sign up, log in, and manage their accounts. The system should support authentication via email/password, Google, and other providers.

##Tasks

- Set up Firebase Authentication in the project.
- Implement email/password authentication with proper validation.
- Enable Google Sign-In for seamless login.
- Create authentication-related UI components (Sign Up, Login, Logout).
- Store user details in Firestore for profile management.
- Implement error handling & authentication state management.
- Ensure role-based access control (e.g., Student, Teacher, Admin).

##Acceptance Criteria

- Users should be able to sign up, log in, and log out.
- Authentication states should persist across sessions.
- Error messages should be displayed for invalid inputs or failed logins.
- User roles should restrict access to specific features.

Labels: authentication, firebase, backend, frontend