Phase 3 PR 16 — concrete OPC UA server scaffolding with AlarmConditionState materialization. Introduces the OPCFoundation.NetStandard.Opc.Ua.Server package (v1.5.374.126, same version the v1 stack already uses) and two new server-side classes: DriverNodeManager : CustomNodeManager2 is the concrete realization of PR 15's IAddressSpaceBuilder contract — Folder() creates FolderState nodes under an Organizes hierarchy rooted at ObjectsFolder > DriverInstanceId; Variable() creates BaseDataVariableState with DataType mapped from DriverDataType (Boolean/Int32/Float/Double/String/DateTime) + ValueRank (Scalar or OneDimension) + AccessLevel CurrentReadOrWrite; AddProperty() creates PropertyState with HasProperty reference. Read hook wires OnReadValue per variable to route to IReadable.ReadAsync; Write hook wires OnWriteValue to route to IWritable.WriteAsync and surface per-tag StatusCode. MarkAsAlarmCondition() materializes an OPC UA AlarmConditionState child of the variable, seeded from AlarmConditionInfo (SourceName, InitialSeverity → UA severity via Low=250/Medium=500/High=700/Critical=900, InitialDescription), initial state Enabled + Acknowledged + Inactive + Retain=false. Returns an IAlarmConditionSink whose OnTransition updates alarm.Severity/Time/Message and switches state per AlarmType string ('Active' → SetActiveState(true) + SetAcknowledgedState(false) + Retain=true; 'Acknowledged' → SetAcknowledgedState(true); 'Inactive' → SetActiveState(false) + Retain=false if already Acked) then calls alarm.ReportEvent to emit the OPC UA event to subscribed clients. Galaxy's GalaxyAlarmTracker (PR 14) now lands at a concrete AlarmConditionState node instead of just raising an unobserved C# event. OtOpcUaServer : StandardServer wires one DriverNodeManager per DriverHost.GetDriver during CreateMasterNodeManager — anonymous endpoint, no security profile (minimum-viable; LDAP + security-profile wire-up is the next PR). DriverHost gains public GetDriver(instanceId) so the server can enumerate drivers at startup. NestedBuilder inner class in DriverNodeManager implements IAddressSpaceBuilder by temporarily retargeting the parent's _currentFolder during each call so Folder→Variable→AddProperty land under the correct subtree — not thread-safe if discovery ran concurrently, but GenericDriverNodeManager.BuildAddressSpaceAsync is sequential per driver so this is safe by construction. NuGet audit suppress for GHSA-h958-fxgg-g7w3 (moderate-severity in OPCFoundation.NetStandard.Opc.Ua.Core 1.5.374.126; v1 stack already accepts this risk on the same package version). PR 16 is scoped as scaffolding — the actual server startup (ApplicationInstance, certificate config, endpoint binding, session management wiring into OpcUaServerService.ExecuteAsync) is deferred to a follow-up PR because it needs ApplicationConfiguration XML + optional-cert-store logic that depends on per-deployment policy decisions. The materialization shape is complete: a subsequent PR adds 100 LOC to start the server and all the already-written IAddressSpaceBuilder + alarm-condition + read/write wire-up activates end-to-end. Full solution: 0 errors, 152 unit tests pass (no new tests this PR — DriverNodeManager unit testing needs an IServerInternal mock which is heavyweight; live-endpoint integration tests land alongside the server-startup PR).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Server/OpcUa/OtOpcUaServer.cs

@@ -0,0 +1,62 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Opc.Ua;
+using Opc.Ua.Server;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.Hosting;
+using ZB.MOM.WW.OtOpcUa.Core.OpcUa;
+
+namespace ZB.MOM.WW.OtOpcUa.Server.OpcUa;
+
+/// <summary>
+///     <see cref="StandardServer"/> subclass that wires one <see cref="DriverNodeManager"/> per
+///     registered driver from <see cref="DriverHost"/>. Anonymous endpoint on
+///     <c>opc.tcp://0.0.0.0:4840</c>, no security — PR 16 minimum-viable scope; LDAP + security
+///     profiles are deferred to their own PR on top of this.
+/// </summary>
+public sealed class OtOpcUaServer : StandardServer
+{
+    private readonly DriverHost _driverHost;
+    private readonly ILoggerFactory _loggerFactory;
+    private readonly List<DriverNodeManager> _driverNodeManagers = new();
+
+    public OtOpcUaServer(DriverHost driverHost, ILoggerFactory loggerFactory)
+    {
+        _driverHost = driverHost;
+        _loggerFactory = loggerFactory;
+    }
+
+    /// <summary>
+    ///     Read-only snapshot of the driver node managers materialized at server start. Used by
+    ///     the generic-driver-node-manager-driven discovery flow after the server starts — the
+    ///     host walks each entry and invokes
+    ///     <c>GenericDriverNodeManager.BuildAddressSpaceAsync(manager)</c> passing the manager
+    ///     as its own <see cref="IAddressSpaceBuilder"/>.
+    /// </summary>
+    public IReadOnlyList<DriverNodeManager> DriverNodeManagers => _driverNodeManagers;
+
+    protected override MasterNodeManager CreateMasterNodeManager(IServerInternal server, ApplicationConfiguration configuration)
+    {
+        foreach (var driverId in _driverHost.RegisteredDriverIds)
+        {
+            var driver = _driverHost.GetDriver(driverId);
+            if (driver is null) continue;
+
+            var logger = _loggerFactory.CreateLogger<DriverNodeManager>();
+            var manager = new DriverNodeManager(server, configuration, driver, logger);
+            _driverNodeManagers.Add(manager);
+        }
+
+        return new MasterNodeManager(server, configuration, null, _driverNodeManagers.ToArray());
+    }
+
+    protected override ServerProperties LoadServerProperties() => new()
+    {
+        ManufacturerName = "OtOpcUa",
+        ProductName = "OtOpcUa.Server",
+        ProductUri = "urn:OtOpcUa:Server",
+        SoftwareVersion = "2.0.0",
+        BuildNumber = "0",
+        BuildDate = DateTime.UtcNow,
+    };
+}