Clean stop

Purpose

Before a machine may disappear — end of day, a spot instance about to reclaim, a container about to be torn down, or just walking away — in-flight work is easy to strand: a commit that never pushed, a branch with no PR, a plan that lives only in a local file, a worktree nobody will find again. This skill sweeps everything touched this session to a durable, linked resting state and reports whether it is genuinely safe to shut down.

Where /session-flow:keep-going recovers a session AFTER an interruption, clean-stop is its go/stop mirror — it makes the interruption safe BEFOREHAND, so there is nothing to recover. It supersedes a local /session-flow:handoff when the machine itself may go away: a handoff file is a machine-local save-point, and a save-point that dies with the disk is no save-point. clean-stop leaves the resumable state where it survives the machine — in the PR and issue bodies on the remote.