Agent Skills: refactor:docker

Refactor Docker configurations to improve security, performance, and maintainability. Transforms insecure Dockerfiles and docker-compose files into production-ready containers following 2025 best practices. Implements multi-stage builds, non-root users, pinned image versions, health checks, secrets management, and network segmentation. Fixes common anti-patterns like running as root, hardcoded credentials, missing .dockerignore, and bloated images.