hyperswitch

0ec9dfee - feat(validation): add backend deprecation validation for mandate_id

feat(validation): add backend deprecation validation for mandate_id - Add DeprecatedFieldsConfig with excluded_merchant_ids and deprecated_fields list - Add DeprecatedField error variant (IR_52) for structured deprecation errors - Implement validate_deprecated_fields() in payments helpers using OnceLock - Excluded merchants: urbanclap, abo_factory (can still use mandate_id) - mandate_id alternative: mandate_data