[TASK] Authentication Logic (Signup & Login)

[PEXEL2002]

Task description and detailed requirements:
Develop the core security features for user access.

• Implement a /register endpoint that hashes passwords using bcrypt.
• Implement a /login endpoint that validates user credentials.
• Set up JWT (JSON Web Token) generation for session management.

Definition of task completion:
A user can be registered and then log in to receive a valid token. Passwords must never be stored in plain text in the database.