docs(docker): integrate Docker Compose deployment guidance

[kirisame-wang]

Summary

• Add references/docker-compose-checklist.md — a standalone checklist covering the most common Docker Compose deployment pitfalls: naming stability, image tag pinning, secret injection, named volumes, network isolation, health checks, and rollback procedure.
• Extend skills/ci-cd-and-automation with a "Containerized Services" section covering CI-side concerns: image tagging strategy (git SHA, never latest), multi-stage Dockerfiles, and a GitHub Actions build-and-push workflow example.
• Extend skills/shipping-and-launch with a Docker Compose–specific pre-deploy checklist block that cross-references the new checklist file.

Motivation

The project had no guidance for containerized deployments. Agents working on Docker Compose projects would fall through to generic deployment advice and miss concrete failure modes (container name drift, latest tag rollback failures, secrets baked into image layers). This change fills that gap without adding a new top-level skill — Docker concerns are distributed into the phase that owns them (CI pipeline → ci-cd-and-automation, deploy checklist → shipping-and-launch).

Test Plan

• references/docker-compose-checklist.md follows the reference file convention (in references/, not inside a skill directory)
• Cross-references in ci-cd-and-automation and shipping-and-launch point to references/docker-compose-checklist.md by correct relative path
• No content is duplicated between the two SKILL.md files — both defer detail to the checklist