Support container image for dewy registry

The dewy container command achieves blue-green deployment by starting a new container (green) on a Docker network and performing health checks. Once healthy, it adds the network alias (e.g., "myapp-current") to the green container while removing it from the old container (blue), instantly switching traffic. After a configurable drain period (default 30s) for existing connections to complete, it gracefully stops and removes the blue container.

$  dewy container \
     --registry oci://ghcr.io/username/myapp \
     --network myapp-net \
     --network-alias myapp-current \
     --container-port 8080 \
     --health-path /health \
     --health-timeout 10s \
     --drain-time 60s \
     --env APP_ENV=production \
     --volume /data:/app/data \
     --log-level info

URI Format: oci://[registry-host]/[path]/[image]?[options]

Registry	URI
Docker Hub	oci://docker.io/username/myapp
GitHub Container Registry	oci://ghcr.io/linyows/myapp?pre-release=true
Google Artifact Registry	oci://us-central1-docker.pkg.dev/project/repo/myapp
AWS ECR	oci://123456789012.dkr.ecr.us-east-1.amazonaws.com/myapp
Private Registry	oci://registry.example.com:5000/myapp

Software that tracks container images:

• Watchtower: Performs deployments as well
• Diun: Only detects and sends notifications

About watchtower:

• For Docker
• Runs as a container itself and monitors running containers via the Docker API (through /var/run/docker.sock)
• Needs access to the Docker socket (effectively root privileges)

$ docker run --detach \
    --name watchtower \
    --volume /var/run/docker.sock:/var/run/docker.sock \
    containrrr/watchtower

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