feat(auditlog): NotifyDeliver rows carry the originating ExecutionId

tests/ScadaLink.Commons.Tests/Messages/NotificationMessagesTests.cs

@@ -40,6 +40,47 @@ public class NotificationMessagesTests
         Assert.Null(msg.SourceScript);
     }
 
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_DefaultsToNull()
+    {
+        // Audit Log #23: OriginExecutionId is an additive trailing member — a
+        // submit built without it (old call sites / old serialized payloads)
+        // leaves the id null.
+        var msg = new NotificationSubmit(
+            "notif-3", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow);
+
+        Assert.Null(msg.OriginExecutionId);
+    }
+
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_RoundTripsWhenSupplied()
+    {
+        var executionId = Guid.NewGuid();
+        var msg = new NotificationSubmit(
+            "notif-4", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow, executionId);
+
+        Assert.Equal(executionId, msg.OriginExecutionId);
+    }
+
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_SurvivesJsonRoundTrip()
+    {
+        // The buffered S&F payload IS a serialized NotificationSubmit; the
+        // forwarder deserializes it, so OriginExecutionId must survive JSON.
+        var executionId = Guid.NewGuid();
+        var msg = new NotificationSubmit(
+            "notif-5", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow, executionId);
+
+        var json = System.Text.Json.JsonSerializer.Serialize(msg);
+        var roundTripped = System.Text.Json.JsonSerializer.Deserialize<NotificationSubmit>(json);
+
+        Assert.NotNull(roundTripped);
+        Assert.Equal(executionId, roundTripped!.OriginExecutionId);
+    }
+
     [Fact]
     public void NotificationSubmit_ValueEquality_EqualWhenAllFieldsMatch()
     {