The commonly used command to create a new migration for ASP.NET Core Identity changes is 'dotnet ef migrations add'. This command generates a new migration file containing the necessary SQL scripts to update the database schema based on changes in your Identity-related code.

Continuous Deployment (CD) is a deployment strategy where code changes are automatically deployed to production after passing automated tests. It enables rapid and reliable software delivery, ensuring that new features and bug fixes are quickly available to users.

The "Build Scripts" would NOT typically be found in the project.json file. Project.json primarily focused on project structure, dependencies, and target frameworks, whereas build scripts were typically defined in other build-related files or tools specific to the build system.

Project.json handled transitive dependencies explicitly, meaning it included both direct and transitive dependencies in the project file. In contrast, the NuGet approach in previous ASP.NET versions handled transitive dependencies implicitly, which required developers to manage them manually. Project.json's explicit handling improved transparency and control over dependencies.

To preserve the user's cart information across sessions, even after they log out, you should utilize Session state with server-side storage. This allows the cart data to be stored on the server, making it persistent across user sessions.

In the MVC (Model-View-Controller) architecture, the 'Model' component handles data-related logic, such as fetching data from a database. It represents the application's data and business logic. The 'Controller' handles user input and coordinates the flow of data between the 'Model' and 'View' components.

To restrict access to registered users only, you would use the [Authorize] attribute. This attribute can be applied at the controller or action level and ensures that only authenticated users can access the specified resources. It doesn't require specifying roles, as it already implies authenticated users. [AllowAnonymous] would allow both anonymous and registered users, while [Authorize(Roles = "Admin")] and [Authorize(Roles = "User")] are role-based authorizations and are not suitable for this scenario.

The primary language used for coding in ASP.NET Core is C#. While ASP.NET Core supports multiple languages, C# is the most commonly used language for building ASP.NET Core applications due to its strong integration with the framework and extensive tooling support.

The Identity middleware in ASP.NET Core primarily handles authentication. It intercepts requests to determine if a user is authenticated and provides features like cookie-based authentication, token-based authentication, and integration with external identity providers (e.g., Google, Facebook) for user login.

In the MVC (Model-View-Controller) design pattern, the Controller is primarily responsible for handling user input and interactions. It receives user requests, processes them, interacts with the Model to retrieve or manipulate data, and determines the appropriate View to render as a response.

In the MVC (Model-View-Controller) pattern, the Model component is responsible for managing the application's data and business logic. In this scenario, it would be responsible for fetching the product details from the database. The Model interacts with the database and provides data to the Controller, which then passes it to the View for rendering.

SignalR is a real-time web framework in ASP.NET Core that enables features like live chat. It allows bi-directional communication between the server and connected clients, making it ideal for building interactive and real-time applications. The other options are not related to live chat functionality.