Mark stored procedure params without defaults as required in OpenAPI

Author: Copilot

src/Core/Services/OpenAPI/OpenApiDocumentor.cs

@@ -1422,7 +1422,10 @@ private static OpenApiSchema CreateSpRequestComponentSchema(Dictionary<string, P
                     Default = def.Default is not null ? new OpenApiString(def.Default) : null
                 });
 
-                if (def.Required == true)
+                // A parameter is required when it is explicitly marked required in the runtime config,
+                // or when no default value is available, in which case a value must be provided in the
+                // request body. This mirrors the logic used by IsRequestBodyRequired.
+                if (def.Required ?? !def.HasConfigDefault)
                 {
                     required.Add(parameter);
                 }

src/Service.Tests/OpenApiDocumentor/StoredProcedureGeneration.cs

@@ -101,6 +101,13 @@ public void ValidateRequestBodyContents(string entityName, string[] expectedPara
                 string expectedSchemaReferenceId = $"{entityName}{OpenApiDocumentor.SP_REQUEST_SUFFIX}";
 
                 ValidateOpenApiReferenceContents(schemaComponentReference, expectedSchemaReferenceId, expectedParameters, expectedParametersJsonTypes);
+
+                // Validate that parameters without a default value are marked as required in the schema component.
+                ISet<string> requiredParameters = _openApiDocument.Components.Schemas[expectedSchemaReferenceId].Required;
+                CollectionAssert.AreEquivalent(
+                    expectedParameters,
+                    requiredParameters.ToArray(),
+                    message: "Unexpected required parameters in request body schema component.");
             }
         }