feat: Implement user authentication

[kaushalpowar]

This pull request introduces user authentication functionality to the application. This is a significant enhancement that improves security and provides a more robust user experience.

Key Features:

• Secure Login System: The login system utilizes bcrypt for password hashing, ensuring that passwords are stored securely and are not vulnerable to common attacks.
• Email Verification: Newly registered users must verify their email addresses before they can log in, adding an extra layer of security and preventing the creation of fake accounts.
• JWT (JSON Web Token) Authentication: JWTs are used for secure session management, providing a stateless and efficient authentication mechanism. This improves scalability and security.
• API Endpoints: New API endpoints have been added for user registration and login, allowing seamless integration with other parts of the application.
• Error Handling and Input Validation: Robust error handling and input validation have been implemented to prevent common security vulnerabilities and provide informative error messages to users.

Implementation Details:

The authentication system is built using [mention libraries/frameworks used, e.g., Node.js, Express.js, bcrypt, jsonwebtoken]. The database schema has been updated to include the necessary fields for user accounts, including hashed passwords and email verification status. Detailed API documentation is included in the docs folder.

Testing:

Thorough testing has been conducted to ensure the functionality and security of the authentication system. Unit tests cover individual components, and integration tests verify the overall functionality.

This feature significantly enhances the application's security and user experience. It allows users to securely manage their accounts and access protected resources. This is a crucial step towards building a more robust and secure application.