feat(v3-batch4-wp3): raw-only binding + UNS fan-out + write routing

Wave B of Batch 4 — the runtime binding seam for the dual namespace.

Applier (both realms, explicit realm at every sink call site):
- MaterialiseRawSubtree: Raw containers as folders + Raw tags as variables
  keyed by RawPath (native-alarm tag → single Part 9 condition at the RawPath),
  all in AddressSpaceRealm.Raw; historian tagname = override else RawPath.
- MaterialiseUnsReferences: each UNS reference Variable under its equipment
  folder (Uns realm) + an Organizes UNS->Raw edge; inherits writable/array/
  historian tagname from the backing raw tag (both NodeIds -> one tagname).
- FeedHistorizedRefs / ProvisionHistorizedTags now source RAW tags (mux ref
  stays single, keyed by RawPath); ApplyPureRemove tears down raw tags + UNS
  refs in place (raw-container removal falls back to rebuild).

DriverHostActor (dual-NodeId, single-source fan-out):
- _nodeIdByDriverRef value gains a realm (NodeRealmRef); rebuilt from
  RawTags UNION UnsReferenceVariables so one (DriverInstanceId, RawPath) fans
  to the raw NodeId AND every referencing UNS NodeId with identical
  value/quality/timestamp. Write inverse map keyed by the bare id; the
  ns-qualified NodeId the write hook passes is normalised (BareNodeId) so a
  write to either NodeId resolves the same driver ref (-> RawPath write).
- Native raw alarm condition routing is realm-tagged (Raw); AttributeValueUpdate
  + AlarmStateUpdate carry the realm through to the sink.

Retire EquipmentNodeIds -> V3NodeIds.Uns (applier/VirtualTagHostActor) and
RawPaths.Combine (DiscoveredNodeMapper, discovered nodes are Raw now).

DeploymentArtifact.ParseComposition emits the Raw + UNS subtrees byte-parity
with the composer (reconstruct entities -> AddressSpaceComposer.Compose).

Sink surface: removed the transitional `= AddressSpaceRealm.Uns` defaults from
IOpcUaAddressSpaceSink / ISurgicalAddressSpaceSink / SdkAddressSpaceSink /
DeferredAddressSpaceSink / NullOpcUaAddressSpaceSink — every call site is now
explicit (realm reordered before the trailing optionals on EnsureVariable +
MaterialiseAlarmCondition). Node-manager convenience methods keep their
defaults (they are not the interface impl; Sdk delegates explicitly).

Tests: rewrote DriverHostActorLiveValueTests (fan-out drift, 1:N) +
DriverHostActorWriteRoutingTests (dual-NodeId raw/uns write routing) to the v3
raw+uns model; new AddressSpaceApplierRawUnsTests; migrated the EquipmentTags
provisioning/feed tests to RawTags; swept EquipmentNodeIds test callers.

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

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DiscoveredNodeMapper.cs

@@ -1,4 +1,5 @@
 using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Commons.Types;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 using ZB.MOM.WW.OtOpcUa.OpcUaServer;
 
@@ -36,8 +37,12 @@ public static class DiscoveredNodeMapper
     /// </param>
     /// <returns>The folders, variables, and routing map to apply against the OPC UA address space.</returns>
     public static DiscoveredInjectionPlan Map(
-        string equipmentId, IReadOnlyList<DiscoveredNode> nodes, IReadOnlySet<string> authoredRefs)
+        string rootNodeId, IReadOnlyList<DiscoveredNode> nodes, IReadOnlySet<string> authoredRefs)
     {
+        // v3 Batch 4: discovered nodes graft onto the RAW device subtree — a discovered node's NodeId is
+        // <rootDevicePath>/<folder…>/<name> (slash-joined RawPath), NOT the retired equipment-scoped
+        // {equipmentId}/{folderPath}/{name}. Root-relative combine (the root is an already-built RawPath).
+        static string Combine(string root, string tail) => root + RawPaths.SeparatorString + tail;
         var kept = nodes.Where(n => !authoredRefs.Contains(n.FullReference)).ToList();
 
         // Device-folder collapse: when every kept node shares one identical index-1 segment (the single
@@ -64,20 +69,20 @@ public static class DiscoveredNodeMapper
             for (var i = 0; i < segs.Count; i++)
             {
                 var folderPath = string.Join('/', segs.Take(i + 1));
-                var nodeId = EquipmentNodeIds.SubFolder(equipmentId, folderPath);
+                var nodeId = Combine(rootNodeId, folderPath);
                 if (folders.ContainsKey(nodeId)) continue;
-                var parent = i == 0 ? equipmentId : EquipmentNodeIds.SubFolder(equipmentId, string.Join('/', segs.Take(i)));
+                var parent = i == 0 ? rootNodeId : Combine(rootNodeId, string.Join('/', segs.Take(i)));
                 folders[nodeId] = new DiscoveredFolder(nodeId, parent, segs[i]);
             }
 
             var varFolderPath = string.Join('/', segs);
-            var varNodeId = EquipmentNodeIds.Variable(equipmentId, varFolderPath, n.BrowseName);
-            // Mirror AddressSpaceApplier.MaterialiseEquipmentTags: a folder-less variable parents directly
-            // at the equipment (SubFolder("", ...) would yield a trailing-slash "EQ-1/" that mismatches the
-            // EquipmentNodeIds.Variable NodeId, which guards IsNullOrWhiteSpace).
+            var varNodeId = string.IsNullOrEmpty(varFolderPath)
+                ? Combine(rootNodeId, n.BrowseName)
+                : Combine(rootNodeId, varFolderPath + RawPaths.SeparatorString + n.BrowseName);
+            // A folder-less variable parents directly at the root device node.
             var varParent = string.IsNullOrEmpty(varFolderPath)
-                ? equipmentId
-                : EquipmentNodeIds.SubFolder(equipmentId, varFolderPath);
+                ? rootNodeId
+                : Combine(rootNodeId, varFolderPath);
             variables.Add(new DiscoveredVariable(
                 varNodeId, varParent, n.DisplayName, ToBuiltinTypeString(n.DataType), n.Writable, n.IsArray, n.ArrayDim));
             routing[n.FullReference] = varNodeId;