refactor(auditlog): rename audit correlation field, add cross-helper tests

src/ScadaLink.SiteRuntime/Scripts/AuditingDbCommand.cs

@@ -37,10 +37,13 @@ internal sealed class AuditingDbCommand : DbCommand
     private readonly string _siteId;
     private readonly string _instanceName;
     private readonly string? _sourceScript;
-    private readonly Guid _correlationId;
+    private readonly Guid _auditCorrelationId;
     private readonly ILogger _logger;
     private DbConnection? _wrappingConnection;
 
+    // Parameter ordering: auditCorrelationId sits immediately after the ILogger,
+    // consistent with the other three audit-threaded ctors (ExternalSystemHelper,
+    // DatabaseHelper, AuditingDbConnection).
     public AuditingDbCommand(
         DbCommand inner,
         IAuditWriter auditWriter,
@@ -48,8 +51,8 @@ internal sealed class AuditingDbCommand : DbCommand
         string siteId,
         string instanceName,
         string? sourceScript,
-        Guid correlationId,
-        ILogger logger)
+        ILogger logger,
+        Guid auditCorrelationId)
     {
         _inner = inner ?? throw new ArgumentNullException(nameof(inner));
         _auditWriter = auditWriter ?? throw new ArgumentNullException(nameof(auditWriter));
@@ -57,8 +60,8 @@ internal sealed class AuditingDbCommand : DbCommand
         _siteId = siteId ?? string.Empty;
         _instanceName = instanceName ?? string.Empty;
         _sourceScript = sourceScript;
-        _correlationId = correlationId;
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
+        _auditCorrelationId = auditCorrelationId;
     }
 
     // -- Forwarded surface ------------------------------------------------
@@ -429,9 +432,10 @@ internal sealed class AuditingDbCommand : DbCommand
             OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
             Channel = AuditChannel.DbOutbound,
             Kind = AuditKind.DbWrite,
-            // Audit Log #23: the execution-wide correlation id, so all the
-            // sync ApiCall/DbWrite rows from one script run share an id.
-            CorrelationId = _correlationId,
+            // Audit Log #23: the execution-wide correlation id, so this sync
+            // DbWrite row shares an id with the other sync trust-boundary rows
+            // from the same script run.
+            CorrelationId = _auditCorrelationId,
             SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
             SourceInstanceId = _instanceName,
             SourceScript = _sourceScript,