Timing: during. Confine the executor's effects so mistakes can't escape.
- computer: sandbox, container, git worktree, VM
- social: prison, quarantine, a clean room
The best neighbor for vibe-linter to annex: a sandbox makes "the door is the only exit" a physical fact, not a string-match (gatekeeper-not-driver door seal). A multi-worktree node is isolation AND tournament at once — it pairs naturally with selection.
Up: control-methods