Clean up and reorganize using/import statements across the solution. Remove unnecessary DTO imports from Application and Infrastructure layers, and ensure Contracts DTOs are only referenced in API and BlazorWebApp layers. No business logic is changed; these updates improve code organization, reduce coupling, and clarify architectural separation between layers.
Refactored DTO class and namespace names from Massdata* to MassData* in DbFirst.Contracts. Updated all relevant application files to use the correct DTO namespaces for Catalogs and MassData. Adjusted _Imports.razor to include new DTO namespaces and removed unused usings. These changes improve code consistency and reduce namespace-related errors.
Removed unused and redundant using/import statements from multiple files, including command, repository, and Program.cs. No functional changes; this commit improves code clarity and organization.
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.