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>

tools/opcuacli-dotnet/Commands/ConnectCommand.cs

@@ -0,0 +1,22 @@
+using CliFx;
+using CliFx.Attributes;
+using CliFx.Infrastructure;
+
+namespace OpcUaCli.Commands;
+
+[Command("connect", Description = "Test connection to an OPC UA server")]
+public class ConnectCommand : ICommand
+{
+    [CommandOption("url", 'u', Description = "OPC UA server endpoint URL", IsRequired = true)]
+    public string Url { get; init; } = default!;
+
+    public async ValueTask ExecuteAsync(IConsole console)
+    {
+        using var session = await OpcUaHelper.ConnectAsync(Url);
+        await console.Output.WriteLineAsync($"Connected to: {session.Endpoint.EndpointUrl}");
+        await console.Output.WriteLineAsync($"Server: {session.Endpoint.Server!.ApplicationName}");
+        await console.Output.WriteLineAsync($"Security Mode: {session.Endpoint.SecurityMode}");
+        await console.Output.WriteLineAsync($"Security Policy: {session.Endpoint.SecurityPolicyUri}");
+        await console.Output.WriteLineAsync("Connection successful.");
+    }
+}