fix(transport): preserve MinTimeBetweenRuns + ExternalSystem retry fields in bundle DTOs

Add TimeSpan? MinTimeBetweenRuns to TemplateScriptDto and int MaxRetries /
TimeSpan RetryDelay to ExternalSystemDto; wire both directions in
EntitySerializer. Extends the existing script round-trip assertion and adds
Roundtrip_external_system_preserves_retry_config.

src/ScadaLink.Transport/Serialization/EntityDtos.cs

@@ -87,7 +87,8 @@ public sealed record TemplateScriptDto(
     string? TriggerConfiguration,
     string? ParameterDefinitions,
     string? ReturnDefinition,
-    bool IsLocked);
+    bool IsLocked,
+    TimeSpan? MinTimeBetweenRuns);
 
 public sealed record TemplateCompositionDto(
     string InstanceName,
@@ -103,6 +104,8 @@ public sealed record ExternalSystemDto(
     string Name,
     string BaseUrl,
     string AuthType,
+    int MaxRetries,
+    TimeSpan RetryDelay,
     IReadOnlyList<ExternalSystemMethodDto> Methods,
     SecretsBlock? Secrets);
 

src/ScadaLink.Transport/Serialization/EntitySerializer.cs

@@ -55,7 +55,8 @@ public sealed class EntitySerializer
                     TriggerConfiguration: s.TriggerConfiguration,
                     ParameterDefinitions: s.ParameterDefinitions,
                     ReturnDefinition: s.ReturnDefinition,
-                    IsLocked: s.IsLocked)).ToList(),
+                    IsLocked: s.IsLocked,
+                    MinTimeBetweenRuns: s.MinTimeBetweenRuns)).ToList(),
                 Compositions: t.Compositions.Select(c => new TemplateCompositionDto(
                     InstanceName: c.InstanceName,
                     ComposedTemplateName: templateNameById.TryGetValue(c.ComposedTemplateId, out var cn) ? cn : string.Empty)).ToList())).ToList(),
@@ -89,6 +90,8 @@ public sealed class EntitySerializer
                     Name: sys.Name,
                     BaseUrl: sys.EndpointUrl,
                     AuthType: sys.AuthType,
+                    MaxRetries: sys.MaxRetries,
+                    RetryDelay: sys.RetryDelay,
                     Methods: methods,
                     Secrets: secrets);
             }).ToList(),
@@ -204,6 +207,7 @@ public sealed class EntitySerializer
                         ParameterDefinitions = s.ParameterDefinitions,
                         ReturnDefinition = s.ReturnDefinition,
                         IsLocked = s.IsLocked,
+                        MinTimeBetweenRuns = s.MinTimeBetweenRuns,
                     });
                 }
                 return t;
@@ -253,6 +257,8 @@ public sealed class EntitySerializer
             {
                 Id = ix + 1,
                 AuthConfiguration = dto.Secrets?.Values.TryGetValue("AuthConfiguration", out var auth) == true ? auth : null,
+                MaxRetries = dto.MaxRetries,
+                RetryDelay = dto.RetryDelay,
             };
             externalSystems.Add(sys);
             foreach (var m in dto.Methods)