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/Configuration/ConfigurationLoadingTests.cs

@@ -0,0 +1,100 @@
+using Microsoft.Extensions.Configuration;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.LmxOpcUa.Host.Configuration;
+
+namespace ZB.MOM.WW.LmxOpcUa.Tests.Configuration
+{
+    public class ConfigurationLoadingTests
+    {
+        private static AppConfiguration LoadFromJson()
+        {
+            var configuration = new ConfigurationBuilder()
+                .AddJsonFile("appsettings.json", optional: false)
+                .Build();
+
+            var config = new AppConfiguration();
+            configuration.GetSection("OpcUa").Bind(config.OpcUa);
+            configuration.GetSection("MxAccess").Bind(config.MxAccess);
+            configuration.GetSection("GalaxyRepository").Bind(config.GalaxyRepository);
+            configuration.GetSection("Dashboard").Bind(config.Dashboard);
+            return config;
+        }
+
+        [Fact]
+        public void OpcUa_Section_BindsCorrectly()
+        {
+            var config = LoadFromJson();
+            config.OpcUa.Port.ShouldBe(4840);
+            config.OpcUa.EndpointPath.ShouldBe("/LmxOpcUa");
+            config.OpcUa.ServerName.ShouldBe("LmxOpcUa");
+            config.OpcUa.GalaxyName.ShouldBe("ZB");
+            config.OpcUa.MaxSessions.ShouldBe(100);
+            config.OpcUa.SessionTimeoutMinutes.ShouldBe(30);
+        }
+
+        [Fact]
+        public void MxAccess_Section_BindsCorrectly()
+        {
+            var config = LoadFromJson();
+            config.MxAccess.ClientName.ShouldBe("LmxOpcUa");
+            config.MxAccess.ReadTimeoutSeconds.ShouldBe(5);
+            config.MxAccess.WriteTimeoutSeconds.ShouldBe(5);
+            config.MxAccess.MaxConcurrentOperations.ShouldBe(10);
+            config.MxAccess.MonitorIntervalSeconds.ShouldBe(5);
+            config.MxAccess.AutoReconnect.ShouldBe(true);
+            config.MxAccess.ProbeStaleThresholdSeconds.ShouldBe(60);
+        }
+
+        [Fact]
+        public void GalaxyRepository_Section_BindsCorrectly()
+        {
+            var config = LoadFromJson();
+            config.GalaxyRepository.ConnectionString.ShouldContain("ZB");
+            config.GalaxyRepository.ChangeDetectionIntervalSeconds.ShouldBe(30);
+            config.GalaxyRepository.CommandTimeoutSeconds.ShouldBe(30);
+        }
+
+        [Fact]
+        public void Dashboard_Section_BindsCorrectly()
+        {
+            var config = LoadFromJson();
+            config.Dashboard.Enabled.ShouldBe(true);
+            config.Dashboard.Port.ShouldBe(8081);
+            config.Dashboard.RefreshIntervalSeconds.ShouldBe(10);
+        }
+
+        [Fact]
+        public void DefaultValues_AreCorrect()
+        {
+            var config = new AppConfiguration();
+            config.OpcUa.Port.ShouldBe(4840);
+            config.MxAccess.ClientName.ShouldBe("LmxOpcUa");
+            config.GalaxyRepository.ChangeDetectionIntervalSeconds.ShouldBe(30);
+            config.Dashboard.Enabled.ShouldBe(true);
+        }
+
+        [Fact]
+        public void Validator_ValidConfig_ReturnsTrue()
+        {
+            var config = LoadFromJson();
+            ConfigurationValidator.ValidateAndLog(config).ShouldBe(true);
+        }
+
+        [Fact]
+        public void Validator_InvalidPort_ReturnsFalse()
+        {
+            var config = new AppConfiguration();
+            config.OpcUa.Port = 0;
+            ConfigurationValidator.ValidateAndLog(config).ShouldBe(false);
+        }
+
+        [Fact]
+        public void Validator_EmptyGalaxyName_ReturnsFalse()
+        {
+            var config = new AppConfiguration();
+            config.OpcUa.GalaxyName = "";
+            ConfigurationValidator.ValidateAndLog(config).ShouldBe(false);
+        }
+    }
+}