Agent task: Finish docker-compose actions by creating and pushing docker. Check to use the n

[scx1332]

This pull request was initialized by file-diff-engine for a codex-backed agent task.

Branch: fde-agent/20260429-211932-95d67489
Base branch: main
Task runner: codex
Model: gpt-5.5
Reasoning effort: high
Reasoning summary: auto
Pull request completion mode: AutoReady
Completion behavior: this task pull request starts as a draft and will be marked ready for review after the agent run completes successfully.

Task:
Finish docker-compose actions by creating and pushing docker.

Check to use the newest versions of the actions.

I want commit number as a tag. If pushed to main mark as latest.

[scx1332]

Plan:

1. Add container packaging for arkiv-storaged with a production Dockerfile that builds the Go binary and runs it in a small runtime image.
2. Add a docker-compose.yml for local service execution using the built image/build context and persistent data volume.
3. Update CI to use the newest verified action tags:
   • actions/checkout@v6.0.2
   • actions/setup-go@v6.4.0
   • golangci/golangci-lint-action@v9.2.0
   • docker/login-action@v4.1.0
   • docker/setup-buildx-action@v4.0.0
   • docker/metadata-action@v6.0.0
   • docker/build-push-action@v7.1.0
4. Add a Docker publish job that builds on pushes, publishes to GHCR, tags each pushed image with the full commit SHA, and also tags latest only when the push is to main.
5. Run local validation for Go tests/build and Docker image build where available.
6. Commit and push the changes to the existing branch fde-agent/20260429-211932-95d67489, then post a completion summary on this PR.