feat(v3-batch4-wp4): multi-notifier native alarms (single ReportEvent → raw + equipment notifiers) + teardown symmetry

Materialize each native alarm ONCE at the raw tag (ConditionId = RawPath, Raw
realm); wire the single condition as an SDK event notifier of each referencing
equipment's UNS folder so one ReportEvent fans to every root without
re-reporting per root (which would break Server-object dedup + Part 9 ack
correlation).

- New sink method WireAlarmNotifiers(alarmNodeId, alarmRealm,
  notifierFolderNodeIds, notifierFolderRealm) on IOpcUaAddressSpaceSink,
  forwarded through DeferredAddressSpaceSink + SdkAddressSpaceSink +
  NullOpcUaAddressSpaceSink (the forwarding-trap guard); auto-covered by the
  DeferredSinkForwardingReflectionTests realm + forwarding guards + a
  hand-written forward test.
- OtOpcUaNodeManager: the normative AddNotifier(isInverse) pair + idempotent
  EnsureFolderIsEventNotifier per equipment folder; tracked per condition in
  _alarmNotifierWiring. Teardown symmetry: RemoveNotifier(bidirectional:true) on
  RebuildAddressSpace, RemoveAlarmConditionNode, and RemoveEquipmentSubtree so no
  inverse-notifier entry leaks across redeploys.
- AddressSpaceApplier.MaterialiseRawSubtree wires notifiers for each native alarm
  tag, resolving its ReferencingEquipmentPaths (Area/Line/Equipment) to the
  EquipmentId folder NodeIds via BuildEquipmentIdByFolderPath.
- AlarmTransitionEvent gains ReferencingEquipmentPaths (empty default); /alerts
  renders the referencing-equipment list as display metadata.
- Un-skipped + rewrote the native-alarm dark tests
  (DriverHostActorNativeAlarmTests x6, DriverHostActorNativeAlarmAckRoutingTests
  x1) for the v3 raw-condition model; new NodeManagerMultiNotifierAlarmTests
  proves multi-notifier wiring + teardown symmetry (no leaked duplicates after a
  re-trip) + applier wiring test.

Claude-Session: https://claude.ai/code/session_01LVneM3eh1UtJxEisFXgmox

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AddressSpaceApplierHierarchyTests.cs

@@ -338,6 +338,7 @@ public sealed class AddressSpaceApplierHierarchyTests : IDisposable
         public void RebuildAddressSpace() { }
         /// <summary>Announces a NodeAdded model-change (stub implementation for testing).</summary>
         public void RaiseNodesAddedModelChange(string affectedNodeId, AddressSpaceRealm realm = AddressSpaceRealm.Uns) { }
+        public void WireAlarmNotifiers(string alarmNodeId, AddressSpaceRealm alarmRealm, IReadOnlyList<string> notifierFolderNodeIds, AddressSpaceRealm notifierFolderRealm) { }
         public void AddReference(string sourceNodeId, AddressSpaceRealm sourceRealm, string targetNodeId, AddressSpaceRealm targetRealm, string referenceType = "Organizes") { }
     }
 }