Review finding (Codex P1), pinned red-first: the marker was tied to
telemetry-plugin lifetime, but receivers key crash detection on its
absence per session. A normally closed session in a long-running host
retired silently (classified as a crash once stale), while a telemetry
reload marked every still-live session as cleanly ended.
The session/disposed handler now emits the marker at the session's own
termination edge before retiring it; the dispose-time sweep only marks
sessions still alive at application teardown (their own edge would fire
unobserved). READMEs restate the marker semantics: telemetry stopped
observing cleanly — a marker followed by more session events is a
telemetry reload, not a session restart.
kingwl
ec38cac8ef