4f7999eac2
Subscribe the host to the cluster alarm-commands DPS topic in PreStart and drive the matching ScriptedAlarmEngine op per inbound AlarmCommand. An ownership filter (engine.LoadedAlarmIds) ignores commands for alarms this node does not own; TimedShelve without UnshelveAtUtc and unknown operations are logged + rejected (never thrown); op failures are caught + logged so a faulting op can't fault the actor. Re-projection is left to the engine's existing OnEvent -> OnEngineEmission path. Handler is a Task-returning ReceiveAsync (the project's AK2003 analyzer forbids an async-void Receive delegate), giving ordered awaited async on the actor thread. Adds 3 TestKit tests: ack drives the engine with mapped args, unowned command ignored, missing-UnshelveAtUtc TimedShelve rejected not thrown.