HistorianAdapterActor fired `_ = EnqueueAsync(...)` per alarm transition
with no in-flight cap, so an alarm storm (a native source re-raising
hundreds of conditions on reconnect) spawned hundreds of concurrent SQLite
inserts that serialised on the file lock and held pool threads. It also kept
a Receive<AlarmHistorianEvent> with no production sender: a transition told
directly AND published on `alerts` would have been historized twice.
Transitions now go to a bounded channel (10000) drained by one loop, so the
sink sees one enqueue at a time in arrival order; a full queue holds the
mailbox (backpressure, nothing dropped); PostStop flushes the queue within
the shared 5 s stop budget. The direct receive is deleted. The gate tests
drive transitions instead; a directly-told AlarmHistorianEvent is shown to
be unhandled against a positive control.
Rebased from the unpushed remed/lane-H2 branch (originally authored 2026-10-22
in session_01Ub9hGmYLQvn9XETzw7CMsT) onto current master.
Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV
Joseph Doherty
64269573e7