Implemented DeliveryTask, Payment, and Sale entities with full CRUD, business logic, and API endpoints. Updated Order/OrderItem for sale linkage and fulfillment tracking. Registered new DbSets and DI services. Revised documentation for delivery, sale, and payment workflows.
Added detailed implementation planning documents for steps 10–23, covering all major feature areas. Updated mainPlan.md to reference these steps, their dependencies, and planning files. No code changes—these documents clarify requirements and guide future development.