InstanceActor.BuildAlarmStatesSnapshot now adds an IsConfiguredPlaceholder
row per configured native source binding that currently has no live
condition, so the Debug View tree can show the binding node even when
quiet. A binding is "quiet" when no retained AlarmStateChanged carries its
NativeSourceCanonicalName (DV-1).
Kind derivation: reuses the exact nativeKind value already computed via
ResolveNativeKind(nativeSource.ConnectionName) at the NativeAlarmActor
creation site and stored in a new _nativeAlarmKinds dictionary -- the
accurate per-binding kind (NativeOpcUa vs NativeMxAccess), not the
NativeOpcUa default.
Tests: Snapshot_QuietNativeBinding_EmitsPlaceholder,
Snapshot_NativeBindingWithLiveCondition_NoPlaceholder.
Joseph Doherty