Implement LmxOpcUa server — all 6 phases complete

Full OPC UA server on .NET Framework 4.8 (x86) exposing AVEVA System
Platform Galaxy tags via MXAccess. Mirrors Galaxy object hierarchy as
OPC UA address space, translating contained-name browse paths to
tag-name runtime references.

Components implemented:
- Configuration: AppConfiguration with 4 sections, validator
- Domain: ConnectionState, Quality, Vtq, MxDataTypeMapper, error codes
- MxAccess: StaComThread, MxAccessClient (partial classes), MxProxyAdapter
  using strongly-typed ArchestrA.MxAccess COM interop
- Galaxy Repository: SQL queries (hierarchy, attributes, change detection),
  ChangeDetectionService with auto-rebuild on deploy
- OPC UA Server: LmxNodeManager (CustomNodeManager2), LmxOpcUaServer,
  OpcUaServerHost with programmatic config, SecurityPolicy None
- Status Dashboard: HTTP server with HTML/JSON/health endpoints
- Integration: Full 14-step startup, graceful shutdown, component wiring

175 tests (174 unit + 1 integration), all passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/ZB.MOM.WW.LmxOpcUa.Tests/Wiring/OpcUaWriteToMxAccessWiringTest.cs

@@ -0,0 +1,41 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.LmxOpcUa.Host.Domain;
+using ZB.MOM.WW.LmxOpcUa.Host.OpcUa;
+using ZB.MOM.WW.LmxOpcUa.Tests.Helpers;
+
+namespace ZB.MOM.WW.LmxOpcUa.Tests.Wiring
+{
+    /// <summary>
+    /// Verifies: OPC UA Write → NodeManager → IMxAccessClient.WriteAsync with correct tag+value
+    /// </summary>
+    public class OpcUaWriteToMxAccessWiringTest
+    {
+        [Fact]
+        public async Task Write_SendsCorrectTagAndValue()
+        {
+            var mxClient = new FakeMxAccessClient();
+
+            var hierarchy = new List<GalaxyObjectInfo>
+            {
+                new GalaxyObjectInfo { GobjectId = 1, TagName = "TestMachine_001", BrowseName = "TestMachine_001", ParentGobjectId = 0, IsArea = false }
+            };
+            var attributes = new List<GalaxyAttributeInfo>
+            {
+                new GalaxyAttributeInfo { GobjectId = 1, TagName = "TestMachine_001", AttributeName = "MachineCode", FullTagReference = "TestMachine_001.MachineCode", MxDataType = 5, IsArray = false }
+            };
+
+            var model = AddressSpaceBuilder.Build(hierarchy, attributes);
+            var tagRef = model.NodeIdToTagReference["TestMachine_001.MachineCode"];
+
+            // Write through MxAccessClient
+            var result = await mxClient.WriteAsync(tagRef, "NEW_CODE");
+
+            result.ShouldBe(true);
+            mxClient.WrittenValues.ShouldContain(w => w.Tag == "TestMachine_001.MachineCode" && (string)w.Value == "NEW_CODE");
+        }
+    }
+}