Lab 2 with Spring Security, JWT auth, and layered architecture

Lab 2: Delivery App with Spring Security

Implements secure REST API with JWT authentication, role-based access control, and layered architecture. All tests passing.

Key features:

• OAuth2/JWT authentication on all endpoints
• ROLE_POSTMAN authorization for delivery completion
• Profile-based security configuration
• Embeddable address persistence
• ArchUnit validation for architectural constraints