lateArrivingProvider

Declared HERE rather than on the resolvers, because this is the object that knows whether a model can arrive late at all.

With discovery off nothing will ever ask the runner, so a role naming an unregistered model under this provider is a typo again and must be fatal again - which is what "off restores the startup-only behaviour" has to mean if it is to mean anything. A resolver cannot make that distinction: it exists either way. See LateArrivingModels.