[codex] Add Docker testbed procedure

[Joncallim]

Summary

• Add a full DockerMap Docker testbed operator procedure.
• Link the runbook from the docs index, sandbox fixture page, and testing plan.

Validation

• git diff --cached --check

Notes

• Docs-only change; live Docker fixture and full test suite were not run locally before commit.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: e72d38761c

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Replace the hard-coded checkout path

In any environment that is not the author's local macOS checkout, following this prerequisite from a fresh shell fails immediately or leaves the operator outside the repo, while every subsequent command uses repo-relative scripts/... paths. Use a generic placeholder such as cd /path/to/DockerMap or tell users to run the commands from their existing repository root so the runbook is actually executable by other maintainers.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Honor the sudo Docker mode in manual checks

For hosts where setup succeeds only through the fixture's supported sudo -n docker fallback, this prerequisite and the later Docker evidence/cleanup commands still invoke bare docker, so the procedure will fail with permission errors even though scripts/dockermap-fixture-up.sh recorded the working command in DOCKER_CMD_TEXT. The runbook should either derive and use that recorded Docker command after sourcing the state file or document the sudo form consistently.

Useful? React with 👍 / 👎.