--force overrides the kill refusal and nothing else (#81). The guarded
worktree is recorded in the retained store with reason force-killed —
never removed — and the outcome names what was kept so a client can say
where the work went. A tree whose guard is clear never needed the
override; force removes it as usual.
The store write happens before teardown, so a failed retention leaves
the session running and every artifact intact. DELETE /api/sessions/:id
takes ?force=true and answers 200 with KillOutcome; the unforced kill
keeps its 204.
Miguel Palhas
b96f18c7cb