Pair exclusion smoke tests with a safe near-miss control

When smoke-testing an exclusion inside a shared poller, pair the excluded case with a near-miss control that safely advances to a non-destructive downstream outcome. This proves both sides of the boundary without treating “nothing happened” as sufficient or sending real notifications.

Prefer the existing scheduled invocation when a public trigger runs unrelated stages; manually trigger only once when those side effects are explicitly acceptable. Verify the decision receipt, persistence absence or presence, and outbound-message absence or presence independently with bounded unique identifiers.

This requires a harmless observable downstream state and does not replace full allowed-path delivery testing when notification delivery is itself the feature.