Introduce interfaces for all API clients and update dependency injection to use these interfaces. Refactor services and components to depend on abstractions instead of concrete implementations, improving testability and maintainability.
Add a private _cachedLayoutUser field to BandLayoutService and update EnsureLayoutUserAsync to cache the layout user value after first retrieval or generation. This avoids repeated localStorage calls and improves performance.
Introduce BandLayoutService and shared models to manage grid band layouts across components. Refactor CatalogsGrid and MassDataGrid to use the new service, removing duplicated layout logic. Update _Imports.razor and register the service in Program.cs for improved maintainability and code reuse.
