Document and expose application health-check endpoints

[kmuwanga83]

📌 Problem

The project includes Spring Boot Actuator, but there is no documentation on how to verify if the application is running correctly.

🎯 Objective

Provide clear documentation for health-check and monitoring endpoints.

✅ Tasks

• Document Actuator endpoints (e.g. /actuator/health)
• Add sample responses
• Provide example curl or browser access
• Ensure endpoints are enabled for development

🧪 Acceptance Criteria

• Health-check endpoints are documented
• Contributors can verify application startup easily
• Example responses are included

💡 Suggested Labels

documentation, backend, devops