Code-review refinement of the live-gw read-back helper: complete a
TaskCompletionSource<double?> from the pump instead of a captured local (explicit
cross-task visibility), pass bufferedUpdateIntervalMs:0 (Advise snapshot needs no
SetBufferedUpdateInterval), and document the Advise->OnDataChange filter. Live re-verified 2/2.
Skip-gated (MXGW_ENDPOINT + GALAXY_MXGW_API_KEY) like GatewayGalaxyAlarmFeedLiveTests.
Covers the two seams the unit suite can only fake in isolation:
- reopen: RecreateAsync + InvalidateHandleCaches re-establish write handles
- write: no-login supervisory write commits + persists (fresh-session read-back)
Live-verified 2/2 against 10.100.0.48:5120 (2026-06-14); skips cleanly in CI.
Joseph Doherty