Implement User Registration and Authentication

Create user registration endpoint in user-service. Implement password hashing and validation using a secure method. Create user authentication endpoint with JWT token issuance. Create registration form for users to input their details (name, email, password). Implement form validation (required fields, email format, password strength). Call backend API to create user upon successful form submission. Display success or error messages based on the response from the backend. Create User model in PostgreSQL with necessary fields (name, email, password_hash, etc.). Set up migrations for the User model. Remove models.py (no longer needed)

Closes #4 (closed)