- Introduced Billing-specific models (Invoice, Product, Discount) and DTOs for catalog, discount, and invoicing functionalities.
- Implemented runtime relationships using RelationshipServiceProvider.
- Refactored `DataPayloadMapper` to `DataPayloadMapper` under `Contract` for improved consistency.
- Added `AcademicProductGenerator` for dynamic product identifiers.
- Streamlined API registry and mapper dependencies across domains.
- Enhanced `AdmissionFeeRateWasSetUp` event to dispatch enriched product data.