Feat- Backend setup and environment testing

[TheDzashe]

Swagger Documentation

• Swagger UI accessible at http://localhost:8080/swagger-ui/index.html
• All current endpoints visible in Swagger UI

Error Handling

• Invalid status value returns 400 Bad Request
• Missing projectId returns validation error
• Negative duration returns validation error
• Database connection failure returns meaningful error

README Documentation

• Prerequisites listed (Java 17, Maven, Docker)
• Database setup commands documented
• Environment configuration explained
• Steps to run the application
• Swagger URL provided for testing