v20250323-9ce7614

Added

• Multi-Asset Support (Alloys): Updated Order and Order Request endpoints to support alloy_id alongside the existing stock_id. This is a preparatory update to support future Alloy Index Token listings, such as the S&P Digital Markets 50.

Changed

• Flexible Schema Validation: Updated response models to treat stock_id and alloy_id as optional fields. This ensures backward compatibility for current stock workflows while clearing the way for future asset types.