feat(application): commands/queries + IProductPricingService (PRD-003)
- IProductPriceRepository (AddAsync/GetByProductIdAsync/GetActiveAsync)
- ProductPriceDto, AddProductPriceCommand/Response, GetProductPricesQuery
- AddProductPriceCommandValidator (FluentValidation + TimeProvider, fecha >= hoy_AR)
- AddProductPriceCommandHandler (TransactionScope AsyncFlow, audit fail-closed)
- GetProductPricesQueryHandler (verifica producto existe, lista vacía válida)
- IProductPricingService + ProductPricingService (GetPriceAtAsync → decimal?)
- DI wiring en DependencyInjection.cs
- 29 tests NSubstitute + FakeTimeProvider, 1081 Application.Tests GREEN
dmolinari
4b0567d252