Update type generation to use snake_case

Author: holtskinner

scripts/generate_types.sh

@@ -33,6 +33,7 @@ uv run datamodel-codegen \
   --class-name A2A \
   --use-standard-collections \
   --use-subclass-enum \
-  --base-class a2a._base.A2ABaseModel
+  --base-class a2a._base.A2ABaseModel \
+  --snake-case-field
 
 echo "Codegen finished successfully."