Refactor code structure for improved readability and maintainability

README.md

@@ -204,6 +204,10 @@ Contributions, issues, and further evolution (LL-HLS, ABR, multi-channel, E2EE)
 - [CHANGELOG.md](CHANGELOG.md) - Version history and completed features.
 - [CONTRIBUTING.md](CONTRIBUTING.md) - Guidelines for contributing to the project.
 - [SETUP.md](SETUP.md) - Complete setup guide with prerequisites, environment configuration, running the application, and troubleshooting.
+- [API.md](API.md) - Implemented WebSocket and REST API reference.
+- [DEPLOYMENT.md](DEPLOYMENT.md) - Production deployment and operations guide.
+- [MONITORING.md](MONITORING.md) - Prometheus and Grafana setup and troubleshooting.
+- [SECURITY.md](SECURITY.md) - Security controls, hardening checklist, and incident baseline.
 - [Architecture Documentation](docs/architecture/README.md) - Full arc42 template with diagrams and decisions.
 - [ADRs](docs/architecture/adr/) - Detailed decision records (ADR-001 to ADR-007).