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.
Introduce MassData feature with new API endpoints for querying and upserting records by customer name. Add DTOs, AutoMapper profile, MediatR CQRS handlers, repository pattern, and MassDataDbContext. Register new services in DI and add MassDataConnection to configuration. Upsert uses stored procedure. Enables full CRUD for Massdata via dedicated API.
