Absent when the deployment needs no functions.
The deployment's declared kind, or DEFAULT_RUNTIME_KIND. Its workflows inherit it.
Autonomous definitions with no subject entry, name ascending. They
contribute no trigger, so they get no watcher, and a deployment whose
autonomous definitions are all subjectless gets none at all. A
'selfHosted' one is in SelfHostedNeeds.startInstances instead.
Autonomous definitions with an emitted watcher whose start.filter
reads in a way that cannot narrow the watched updates, name ascending: it
reads the document in a way no field path describes, reads another
document, or reads the clock. Their watcher cannot rule out any update to
a watched type.
Autonomous definitions with an emitted watcher whose subject declares no
types, name ascending. Their watcher is narrowed by no document type, so every document in the dataset but the engine's own can invoke it. Which writes qualify is the update narrowing's answer.