Projection returned from the lifecycle transformer's init().
The local StreamChannel is closed automatically when the transformer
finalizes or fails. _lifecycleLog is intentionally underscore-prefixed to
signal that it is consumed by the run stream wiring
(see run-stream.ts) and not meant for direct user access -
consumers should read run.lifecycle instead.
The lifecycle iterable is the root-scoped projection (prefix
[], starting at offset 0) mirroring the pattern used by the
subgraph discovery transformer. Root stream wiring consumes it
via SET_LIFECYCLE_ITERABLE; child streams are wired with their
own path-scoped iterable produced by filterLifecycleEntries.
interface LifecycleProjection