feat(phase7): route OPC UA Part 9 Acknowledge/Confirm methods to ScriptedAlarmEngine (task #24)

Gap 1 of phase-7-status.md. Intercepts AcknowledgeableConditionType_Acknowledge and
AcknowledgeableConditionType_Confirm calls in DriverNodeManager.Call and dispatches
them to ScriptedAlarmEngine so OPC UA HMI clients can acknowledge/confirm scripted alarms
in addition to the existing Admin UI path. Shelve methods deferred (per-instance NodeIds,
not well-known type MethodIds — follow-up task). AlarmEngine is now exposed through
Phase7ComposedSources so the server wire-up passes it to every DriverNodeManager. 13 new
unit tests cover dispatch kernel, identity fallback, batch handling, and error paths.

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

src/Server/ZB.MOM.WW.OtOpcUa.Server/OpcUaServerService.cs

@@ -56,7 +56,8 @@ public sealed class OpcUaServerService(
             // — late binding after server start is rejected with InvalidOperationException.
             // No-op when the generation has no virtual tags or scripted alarms.
             var phase7 = await phase7Composer.PrepareAsync(gen, stoppingToken);
-            applicationHost.SetPhase7Sources(phase7.VirtualReadable, phase7.ScriptedAlarmReadable);
+            applicationHost.SetPhase7Sources(phase7.VirtualReadable, phase7.ScriptedAlarmReadable,
+                phase7.AlarmEngine);
 
             // Phase 6.2 Stream C wiring — build the AuthorizationGate + NodeScopeResolver
             // from the published generation's NodeAcl rows and the populated equipment