Add docker-compose support with environment variable configuration

- Create docker-compose.yml with server and agent services
- Add environment variable support to Dockerfiles via entrypoint scripts
- Configure server with ADDR, PORT, USERNAME, PASSWORD vars
- Configure agent with SERVER, INTERVAL, AGENT_ID vars
- Add health check to server service for container orchestration
- Add service dependencies to ensure server starts before agent
- Create .dockerignore to optimize Docker builds
- Update QUICKSTART.md with Docker Compose instructions
- Support running server only, agent only, or full stack
- Support multiple agents with custom identifiers

Dockerfile.server

@@ -43,6 +43,14 @@ EXPOSE 8080
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
     CMD wget --quiet --tries=1 --spider http://localhost:8080/login || exit 1
 
+# Create entrypoint script to handle environment variables
+RUN echo '#!/bin/sh\n\
+ADDR=${ADDR:-0.0.0.0}\n\
+PORT=${PORT:-8080}\n\
+USERNAME=${USERNAME:-admin}\n\
+PASSWORD=${PASSWORD:-admin}\n\
+exec ./nerd-monitor-server -addr "$ADDR" -port "$PORT" -username "$USERNAME" -password "$PASSWORD"\n\
+' > /app/entrypoint.sh && chmod +x /app/entrypoint.sh
+
 # Run the server
-ENTRYPOINT ["./nerd-monitor-server"]
-CMD ["-addr", "0.0.0.0", "-port", "8080"]
+ENTRYPOINT ["/app/entrypoint.sh"]