Complete Promptkit batch execution cutover

internal/config/load.go

@@ -59,6 +59,9 @@ func mergeFile(cfg *Config, path string) error {
 	if err != nil {
 		return fmt.Errorf("read config %q: %w", path, err)
 	}
+	if err := rejectRetiredExecutionConfig(data); err != nil {
+		return fmt.Errorf("parse config %q: %w", path, err)
+	}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
 		return fmt.Errorf("parse config %q: %w", path, err)
 	}
@@ -70,3 +73,20 @@ func mergeFile(cfg *Config, path string) error {
 	}
 	return nil
 }
+
+func rejectRetiredExecutionConfig(data []byte) error {
+	var document yaml.Node
+	if err := yaml.Unmarshal(data, &document); err != nil {
+		return err
+	}
+	if len(document.Content) == 0 || document.Content[0].Kind != yaml.MappingNode {
+		return nil
+	}
+	root := document.Content[0]
+	for i := 0; i+1 < len(root.Content); i += 2 {
+		if root.Content[i].Value == "scriptorium" {
+			return fmt.Errorf("scriptorium configuration is no longer supported; migrate to promptkit configuration")
+		}
+	}
+	return nil
+}