US07 - Implement User Registration Backend Service API

[RamirezJM]

As a New Visitor
I need to create a secure account with my email and personal details
So that I can access the SecondChance platform features to donate or claim recycled items.

Details and Assumptions

• The registration service must validate input data (e.g., proper email format, password strength).
• User passwords must be securely hashed (e.g., using bcrypt) before being saved to MongoDB.

Acceptance Criteria

Given a new user provides valid registration details
When a POST request is made to the registration endpoint
Then the service should hash the password, save the new user record, and return a 201 Created response