The systemd sync timer runs git without HOME set, so git config --global (which writes /root/.gitconfig) is invisible to the timer's process — the timer fails with 'could not read Username' silently. Switching to --system writes to /etc/gitconfig which is HOME-agnostic. Migration for already-bootstrapped hosts captured in agent-enrollment.md troubleshooting. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>