Create and drive GitHub Codespaces entirely from the gh CLI: create, ssh, ports forward, cp, logs, stop, delete

Documented steps

1. Authenticate once with gh auth login (needs codespace scope; gh auth refresh -h github.com -s codespace adds it)
2. Create: gh codespace create -R OWNER/REPO -b BRANCH -m MACHINE_TYPE (also useful: --devcontainer-path, --display-name, --idle-timeout 45m); list machine types via the error message or gh api
3. Inspect: gh codespace list shows name, repo, branch, state; most commands take -c CODESPACE_NAME or prompt interactively
4. Work inside it: gh codespace ssh -c NAME for a shell; gh codespace code -c NAME opens VS Code
5. Networking: gh codespace ports -c NAME to list, gh codespace ports forward 8000:8000 -c NAME to tunnel to localhost, gh codespace ports visibility 8000:public -c NAME to share
6. Files & logs: gh codespace cp local.txt 'remote:/workspaces/REPO/' (-r for dirs, remote: prefix for codespace paths); gh codespace logs -c NAME for creation logs
7. Lifecycle: gh codespace stop -c NAME (stops compute billing, storage continues); gh codespace delete -c NAME (or --days N to bulk-delete old ones)
8. Docs: https://cli.github.com/manual/gh_codespace | https://docs.github.com/en/codespaces/developing-in-a-codespace/using-github-codespaces-with-github-cli