fix(opcuaserver): UNS reference nodes repair on backing-tag historian/shape edits

Adversarial review of 9f68f272 (classifier: non-alarm raw-tag deltas became
surgical) found stale UNS inheritance after a surgical raw edit. Editing a raw
tag's IsHistorized / HistorianTagname / IsArray / ArrayLength left every
referencing UNS node STALE: none of those fields were on UnsReferenceVariable,
so no coincident UnsReferenceDelta fired; the applier updated the raw node in
place; and EnsureVariable early-returns on an existing node. Consequences:
HistoryRead through the UNS NodeId served a different series than through the
raw NodeId (breaking the documented dual-registration invariant), a
de-historized tag kept serving history via UNS, and a scalar->array flip left
the UNS mirror scalar AND writable (bypassing the array read-only write gate).

UnsReferenceVariable now carries Backing{IsHistorized,HistorianTagname,IsArray,
ArrayLength}, copied from the backing tag's TagConfigIntent at compose time, so
record equality makes the reference Changed in the SAME plan. Both deltas are
non-rebuild kinds, so the existing machinery repairs the mirror surgically:
remove-previous in Apply, recreate in MaterialiseUnsReferences. That pass now
reads the four values from the RECORD (the single truth the planner diffed)
instead of a rawByPath back-lookup, preserving historian resolution exactly
(blank override => BackingRawPath, which is the backing tag's NodeId).

The artifact-decode seam needs no change: DeploymentArtifact.BuildRawAndUnsSubtrees
drives AddressSpaceComposer.Compose verbatim, which is what guarantees byte-parity.
The classifier needs no change either (a UnsReferenceDelta never forces Rebuild);
its comment now records why.

Also from the same review: a three-place-contract comment on RawTagPlan's
hand-written Equals naming its two downstream consumers, plus classifier pins for
the .Any(!eligible) quantifier, an ArrayLength-only delta, and an
alarm-content-only delta.

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

@@ -20,7 +20,7 @@ public sealed class AddressSpacePlannerDualNamespaceTests
 
     // Compose a fixture with one raw tag (given name) under Plant/Modbus1/PLC-A and one UNS reference to it
     // (with an optional display-name override so the effective name can be held stable across a raw rename).
-    private static AddressSpaceComposition Compose(string tagName, string? displayOverride)
+    private static AddressSpaceComposition Compose(string tagName, string? displayOverride, string tagConfig = "{}")
     {
         var folder = new RawFolder { RawFolderId = "raw-plant", ClusterId = "c1", Name = RawFolderName };
         var driver = new DriverInstance
@@ -32,7 +32,7 @@ public sealed class AddressSpacePlannerDualNamespaceTests
         var tag = new Tag
         {
             TagId = "t-speed", DeviceId = "dev-1", Name = tagName,
-            DataType = "Float", AccessLevel = TagAccessLevel.ReadWrite, TagConfig = "{}",
+            DataType = "Float", AccessLevel = TagAccessLevel.ReadWrite, TagConfig = tagConfig,
         };
         var area = new UnsArea { UnsAreaId = "area-1", ClusterId = "c1", Name = "filling" };
         var line = new UnsLine { UnsLineId = "line-1", UnsAreaId = "area-1", Name = "line-1" };
@@ -219,6 +219,55 @@ public sealed class AddressSpacePlannerDualNamespaceTests
         _ = prev;
     }
 
+    /// <summary>
+    ///     <b>THE PIN (2026-08-15 surgical-deploys review):</b> a RAW-side edit to the backing tag's historian
+    ///     intent or array shape must produce a <c>ChangedRawTags</c> delta AND a <b>coincident</b>
+    ///     <c>ChangedUnsReferenceVariables</c> delta on every reference to it. The coincident delta is the ONLY
+    ///     repair trigger for the UNS mirror node: the raw node is updated surgically in place and
+    ///     <c>EnsureVariable</c> early-returns on the existing UNS node, so without this delta the mirror keeps
+    ///     the OLD historian tagname (HistoryRead via the UNS NodeId serves a different series than via the raw
+    ///     NodeId) and the OLD shape (a scalar→array flip leaves it scalar AND writable). Nothing about the
+    ///     reference ROW changed here — only the backing tag's TagConfig — so the delta exists purely because
+    ///     the four <c>Backing*</c> fields are on <see cref="UnsReferenceVariable"/>.
+    /// </summary>
+    [Theory]
+    [InlineData("{\"isHistorized\":true,\"historianTagname\":\"WW.Old\"}", "{\"isHistorized\":true,\"historianTagname\":\"WW.New\"}")]
+    [InlineData("{\"isHistorized\":true}", "{}")]
+    [InlineData("{}", "{\"isArray\":true,\"arrayLength\":8}")]
+    [InlineData("{\"isArray\":true,\"arrayLength\":8}", "{\"isArray\":true,\"arrayLength\":16}")]
+    public void Backing_tag_historian_or_shape_edit_produces_a_coincident_uns_reference_delta(string before, string after)
+    {
+        var prev = Compose("Speed", displayOverride: null, tagConfig: before);
+        var next = Compose("Speed", displayOverride: null, tagConfig: after);
+
+        var plan = AddressSpacePlanner.Compute(prev, next);
+
+        // Raw side: an attribute edit on a stable RawPath ⇒ a Changed delta (not remove+add).
+        var rawDelta = plan.ChangedRawTags.ShouldHaveSingleItem();
+        rawDelta.Previous.NodeId.ShouldBe(rawDelta.Current.NodeId);
+
+        // UNS side: the SAME reference row, same NodeId + BackingRawPath — flagged Changed ONLY because the
+        // inherited backing historian/shape moved. This is what drives the applier's remove+recreate repair.
+        var unsDelta = plan.ChangedUnsReferenceVariables.ShouldHaveSingleItem();
+        unsDelta.Previous.UnsTagReferenceId.ShouldBe("ref-1");
+        unsDelta.Previous.NodeId.ShouldBe(unsDelta.Current.NodeId);
+        unsDelta.Previous.BackingRawPath.ShouldBe(unsDelta.Current.BackingRawPath);
+        unsDelta.Previous.ShouldNotBe(unsDelta.Current);
+
+        // And the inherited values on the CURRENT side match the backing tag's new intent, so the recreate
+        // materialises the mirror from the same truth the raw node was updated with.
+        unsDelta.Current.BackingIsHistorized.ShouldBe(rawDelta.Current.IsHistorized);
+        unsDelta.Current.BackingHistorianTagname.ShouldBe(rawDelta.Current.HistorianTagname);
+        unsDelta.Current.BackingIsArray.ShouldBe(rawDelta.Current.IsArray);
+        unsDelta.Current.BackingArrayLength.ShouldBe(rawDelta.Current.ArrayLength);
+
+        // Neither realm sees a structural add/remove — this stays a surgical, subscription-preserving deploy.
+        plan.AddedRawTags.ShouldBeEmpty();
+        plan.RemovedRawTags.ShouldBeEmpty();
+        plan.AddedUnsReferenceVariables.ShouldBeEmpty();
+        plan.RemovedUnsReferenceVariables.ShouldBeEmpty();
+    }
+
     /// <summary>Identical compositions diff to an empty plan across both realms (fresh list instances must
     /// not spuriously flag RawTags/UnsReferenceVariables as changed).</summary>
     [Fact]