Controls explicitly-staged pipeline runs: start a named pipeline, list and inspect runs, approve or reject a waiting stage, signal stage completion, watch a run live, cancel a run, and sweep all active runs forward one stage. Pipelines are an ordered, gated sequencing mechanism distinct from the event-driven reactive chain.
Starting a run (fleet pipeline run) is license-gated. The reactive chain (watcher + subscriptions + fabric events) is the primary coordination model; pipelines are a separate mechanism.