A JobBuilder holds pending nodes that are not in the graph yet — it is
the thing you declare into. Naming the alias Job claimed it was the work
itself, and the name propagated into every parameter derived from it
(job: super::Job in run_node read as if it carried the DAG).
Prose uses meaning the job *queue* are left alone: main.rs's "Job-queue
scheduler" comment and the docs/coordinator.md reference.
315 tests pass unchanged.
379c9bb570