feat(site-runtime): add SourceNode column to OperationTracking + thread through RecordEnqueueAsync

src/ScadaLink.AuditLog/Site/Telemetry/CachedCallTelemetryForwarder.cs

@@ -128,12 +128,16 @@ public sealed class CachedCallTelemetryForwarder : ICachedCallTelemetryForwarder
                     // Enqueue — insert-if-not-exists with the operational
                     // channel as the kind discriminator. RetryCount is fixed
                     // at 0 by the tracking store's INSERT contract.
+                    // sourceNode plumbed through but left null here; stamping
+                    // is wired in a later task (Task 14) once the
+                    // INodeIdentityProvider is threaded into the forwarder.
                     await _trackingStore.RecordEnqueueAsync(
                         telemetry.Operational.TrackedOperationId,
                         telemetry.Operational.Channel,
                         telemetry.Operational.Target,
                         telemetry.Audit.SourceInstanceId,
                         telemetry.Audit.SourceScript,
+                        sourceNode: null,
                         ct).ConfigureAwait(false);
                     break;