feat(examples): add Docker health check to all Docker examples

[comxd]

Summary

Add health check functionality to all Docker examples for better container orchestration support (Docker, Kubernetes, ECS, etc.):

• Add /api/health endpoint returning { status: "ok" }
• Add curl package to Alpine images for health check command
• Add HEALTHCHECK instruction to all production Dockerfiles

Affected examples

• with-docker
• with-docker-compose
• with-docker-multi-env

Test plan

• [ ] Build Docker image for each example
• [ ] Verify /api/health endpoint returns { status: "ok" }
• [ ] Verify docker inspect --format='{{.State.Health.Status}}' returns healthy

[ijjk]

Allow CI Workflow Run

• [ ] approve CI run for commit: 34793b5fe2fe621eec40f2b685db3990f2705c92

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer