router.update.channel names the nixpkgs branch to follow (unstable or a
release like 26.05). router-upgrade check compares its newest tested
revision with the running one; preview locks a copy of the configuration
flake to it and lists the packages that change version and the size of the
download without fetching anything; download fetches it; apply takes the
lock and activates with commit-confirm, the lock going back on a rollback
or a failed build. router-update keeps an upgraded nixpkgs pinned.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AeFqV9dZrK6nipHkPfyM4F
