feat(v3-batch4-wp2): node manager dual-namespace + realm-aware sink surface

Register both v3 namespaces (Raw first, UNS second) on OtOpcUaNodeManager and
thread an AddressSpaceRealm discriminator through every node-naming sink method
so a bare node id is resolved to the correct namespace by realm — never parsed
out of the id string.

- IOpcUaAddressSpaceSink / ISurgicalAddressSpaceSink: every node-naming method
  gains `AddressSpaceRealm realm = AddressSpaceRealm.Uns` (transitional default so
  un-migrated WP3 call sites still compile; WP3/Wave B makes them explicit and
  removes the default). Null + SdkAddressSpaceSink impls updated; DeferredAddress-
  SpaceSink forwards realm through every method (the forwarding trap).
- DeferredSinkForwardingReflectionTests: existing exhaustive-forwarding guard
  auto-covers the new signatures; added an explicit guard that every node-naming
  sink method carries an AddressSpaceRealm parameter (RebuildAddressSpace exempt).
- OtOpcUaNodeManager: register RawNamespaceUri + UnsNamespaceUri; realm->namespace
  index via NamespaceIndexForRealm; all node maps (_variables/_folders/
  _alarmConditions/_nativeAlarmNodeIds/_historizedTagnames/_eventNotifierSources)
  re-keyed by the full ns-qualified NodeId string so Raw and UNS nodes sharing a
  bare id stay distinct; _notifierFolders already NodeId-keyed. A historized UNS
  reference node registers the SAME historian tagname as its backing raw node
  (both NodeIds -> one tagname). Inbound-write hook routes the full ns-qualified
  NodeId to the write gateway (realm-aware) and reverts by bare id + realm.
  HistoryRead seams resolve via NodeId directly. DefaultNamespaceUri kept as a
  transitional alias to UnsNamespaceUri for the SubscriptionSurvivalTests.
- Test doubles across Commons.Tests / OpcUaServer.Tests / Runtime.Tests updated to
  the new interface signatures; SdkAddressSpaceSinkTests asserts the UNS namespace
  index for default-realm nodes.

Build: dotnet build ZB.MOM.WW.OtOpcUa.slnx = 0 errors.
Tests: Commons.Tests 310/310; OpcUaServer.Tests 335 passed / 4 pre-existing skips.

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

tests/Server/ZB.MOM.WW.OtOpcUa.Runtime.Tests/Observability/OtOpcUaTelemetryHookTests.cs

@@ -194,24 +194,24 @@ public sealed class OtOpcUaTelemetryHookTests : RuntimeActorTestBase
         /// <param name="value">The value being written.</param>
         /// <param name="quality">The OPC UA quality status.</param>
         /// <param name="sourceTimestampUtc">The source timestamp in UTC.</param>
-        public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc) => Writes++;
+        public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc, AddressSpaceRealm realm = AddressSpaceRealm.Uns) => Writes++;
         /// <summary>Records an alarm condition write.</summary>
         /// <param name="alarmNodeId">The alarm node identifier.</param>
         /// <param name="state">The full condition state snapshot.</param>
         /// <param name="occurredUtc">The time the alarm occurred in UTC.</param>
-        public void WriteAlarmCondition(string alarmNodeId, AlarmConditionSnapshot state, DateTime occurredUtc) => Writes++;
+        public void WriteAlarmCondition(string alarmNodeId, AlarmConditionSnapshot state, DateTime occurredUtc, AddressSpaceRealm realm = AddressSpaceRealm.Uns) => Writes++;
         /// <summary>Materialises an alarm condition (stub implementation).</summary>
         /// <param name="alarmNodeId">The alarm node identifier.</param>
         /// <param name="equipmentNodeId">The equipment folder node identifier.</param>
         /// <param name="displayName">The condition display name.</param>
         /// <param name="alarmType">The domain alarm type.</param>
         /// <param name="severity">The domain severity.</param>
-        public void MaterialiseAlarmCondition(string alarmNodeId, string equipmentNodeId, string displayName, string alarmType, int severity, bool isNative = false) { }
+        public void MaterialiseAlarmCondition(string alarmNodeId, string equipmentNodeId, string displayName, string alarmType, int severity, bool isNative = false, AddressSpaceRealm realm = AddressSpaceRealm.Uns) { }
         /// <summary>Ensures folder exists (stub implementation).</summary>
         /// <param name="folderNodeId">The folder node identifier.</param>
         /// <param name="parentNodeId">The parent folder node identifier.</param>
         /// <param name="displayName">The display name for the folder.</param>
-        public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName) { }
+        public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName, AddressSpaceRealm realm = AddressSpaceRealm.Uns) { }
         /// <summary>Ensures variable exists (stub implementation).</summary>
         /// <param name="variableNodeId">The variable node identifier.</param>
         /// <param name="parentFolderNodeId">The parent folder node identifier.</param>
@@ -219,10 +219,10 @@ public sealed class OtOpcUaTelemetryHookTests : RuntimeActorTestBase
         /// <param name="dataType">The OPC UA built-in type name.</param>
         /// <param name="writable">Whether the node is created read/write.</param>
         /// <param name="historianTagname">The resolved historian tagname (null ⇒ not historized).</param>
-        public void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType, bool writable, string? historianTagname = null, bool isArray = false, uint? arrayLength = null) { }
+        public void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType, bool writable, string? historianTagname = null, bool isArray = false, uint? arrayLength = null, AddressSpaceRealm realm = AddressSpaceRealm.Uns) { }
         /// <summary>Rebuilds address space (recorded via span).</summary>
         public void RebuildAddressSpace() { /* recorded via span */ }
         /// <summary>Announces a NodeAdded model-change (stub implementation).</summary>
-        public void RaiseNodesAddedModelChange(string affectedNodeId) { }
+        public void RaiseNodesAddedModelChange(string affectedNodeId, AddressSpaceRealm realm = AddressSpaceRealm.Uns) { }
     }
 }