Replaced direct service usage in CatalogsController with MediatR-based commands and queries for all CRUD operations. Added command/query and handler classes for Catalog operations. Updated dependency injection to register MediatR and removed ICatalogService. Improved code maintainability and testability by adopting CQRS architecture.
Refactored dependency injection by introducing AddApplication and AddInfrastructure extension methods for service registration. Moved DbContext and AutoMapper setup out of Program.cs to improve modularity and reusability. Added required NuGet packages to .csproj files.