feat(opcua): F10b SDK NodeManager binding — real OPC UA address-space writes

OtOpcUaNodeManager + SdkAddressSpaceSink: the v2 IOpcUaAddressSpaceSink
seam now has a production adapter against a real Opc.Ua.Server
CustomNodeManager2. Writes through OpcUaPublishActor's sink materialise
as real OPC UA Variable updates that subscribed clients see via the
standard ClearChangeMasks notification path.

OtOpcUaNodeManager (CustomNodeManager2):
  - Owns a ConcurrentDictionary<string, BaseDataVariableState> under a
    single namespace (https://zb.com/otopcua/ns) hung off Objects/.
  - WriteValue lazy-creates the variable on first write, sets Value +
    StatusCode (mapped from OpcUaQuality severity bits) + SourceTimestamp,
    then ClearChangeMasks to notify subscribers.
  - WriteAlarmState surfaces a [active, acknowledged] pair on a
    dedicated node id — full AlarmConditionState/event firing comes
    with #85 F14b (EquipmentNodeWalker SDK integration).
  - RebuildAddressSpace tears down every registered variable + clears
    the dictionary so the next write-pass starts fresh.
  - Address-space root folder is materialised in CreateAddressSpace.

SdkAddressSpaceSink: thin IOpcUaAddressSpaceSink → OtOpcUaNodeManager
bridge. Production DI binding (#108) constructs this once the host's
StandardServer has booted.

OtOpcUaSdkServer (StandardServer subclass): overrides
CreateMasterNodeManager to inject OtOpcUaNodeManager via the
MasterNodeManager additionalManagers ctor. NodeManager property
exposes the live instance so OpcUaApplicationHost callers can wrap
it in a sink.

Tests: OpcUaServer 20 -> 24 (+4):
- WriteValue creates + updates variables in the manager
- WriteAlarmState creates a node distinct from value writes
- RebuildAddressSpace clears everything; subsequent writes start fresh
- NullOpcUaAddressSpaceSink no-op sanity

Each test boots a real OpcUaApplicationHost on a free port with the
SDK certificate auto-create flow (F13a) intact — full integration
slice on macOS.

All 6 v2 test suites green: 167 tests passing.

F10 status updated to reflect SDK binding shipped. Residuals:
- #109 OpcUaPublishActor.RebuildAddressSpace → Phase7Applier wiring
- #108 Host DI default to SdkAddressSpaceSink when hasDriver
- #85 F14b EquipmentNodeWalker integration (proper AlarmConditionState
  + folder hierarchy)
- IServiceLevelPublisher SDK binding (writes Server.ServiceLevel node)

src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/SdkAddressSpaceSink.cs

@@ -0,0 +1,28 @@
+using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+
+namespace ZB.MOM.WW.OtOpcUa.OpcUaServer;
+
+/// <summary>
+///     Production <see cref="IOpcUaAddressSpaceSink"/> binding for v2 — bridges
+///     OpcUaPublishActor's writes to the SDK address space owned by
+///     <see cref="OtOpcUaNodeManager"/>. The host wires this in once the StandardServer has
+///     been started (so the node manager exists).
+/// </summary>
+public sealed class SdkAddressSpaceSink : IOpcUaAddressSpaceSink
+{
+    private readonly OtOpcUaNodeManager _nodeManager;
+
+    public SdkAddressSpaceSink(OtOpcUaNodeManager nodeManager)
+    {
+        ArgumentNullException.ThrowIfNull(nodeManager);
+        _nodeManager = nodeManager;
+    }
+
+    public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc)
+        => _nodeManager.WriteValue(nodeId, value, quality, sourceTimestampUtc);
+
+    public void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime sourceTimestampUtc)
+        => _nodeManager.WriteAlarmState(alarmNodeId, active, acknowledged, sourceTimestampUtc);
+
+    public void RebuildAddressSpace() => _nodeManager.RebuildAddressSpace();
+}