merge: external-system retry policy end-to-end (register row 27) — MaxRetries/RetryDelay now travel artifact→gRPC→site schema→S&F enqueue, CLI --max-retries/--retry-delay-seconds, ArtifactDiff compares them

tests/ZB.MOM.WW.ScadaBridge.Communication.Tests/SiteCommandSamples.cs

@@ -217,8 +217,12 @@ internal static class SiteCommandSamples
     private static SharedScriptArtifact SharedScript() =>
         new("Calc", "return 1;", "{\"p\":\"int\"}", "{\"r\":\"int\"}");
 
+    // MaxRetries/RetryDelay are non-default on purpose: they are the deferred-work-row-27
+    // additions (proto fields 7-8), and the generic round-trip assertion is what pins them
+    // to the wire. A sample left at the defaults would round-trip vacuously.
     private static ExternalSystemArtifact ExternalSystem() =>
-        new("Mes", "https://mes/api", "ApiKey", "{\"key\":\"x\"}", "[{\"name\":\"Post\"}]", 45);
+        new("Mes", "https://mes/api", "ApiKey", "{\"key\":\"x\"}", "[{\"name\":\"Post\"}]", 45,
+            MaxRetries: 12, RetryDelay: TimeSpan.FromSeconds(20));
 
     private static DataConnectionArtifact DataConnection() =>
         new("Plc1", "OpcUa", "{\"url\":\"opc.tcp://a\"}", "{\"url\":\"opc.tcp://b\"}", 5);