Owner-backed monotonic active-lifecycle marker.

A fresh marker belongs to its creating process, remains linked to it, may be claimed by exactly one prepared run, is consumed once, and admits at most one owned build. The marker also monitors its creator so even a normal owner exit closes it. Lifecycle state then changes monotonically from false to true. Crossing that boundary makes active-only operations admissible; it does not by itself prove that provider-facing work ran. Producers accumulate that evidence at their dispatch sites. Every transition runs as one operation inside the owner process. Calls carry a server-checked monotonic deadline and allow a short reply grace, so they remain bounded without a timed-out queued transition later mutating the marker.