Rewrite docs/RUNBOOK-PhaseC.md as a full manual-command reference: every
ci_orchestrator command with a working example as the ci-runner user, the `ci`
alias setup, quick-reference table, manual VM lifecycle (incl. vm open GUI
launch with the xhost/--display procedure), templating, maintenance, Phase C
testing, cutover checklist and a troubleshooting map.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
