Clarifications regarding use of DTO

[zensabbah]

With my colleagues, we have some doubts regarding the the implementation of the architecture.

First , why in CompanyRepositoryInterface there are the DTO classes if the domain should be decoupled from the other layers?
Is not responsability of the application layer to connect the business logic with the infrastructure?

Secondly, why User domain is inside Agenda and not inside Auth, since JWTAuth and other classes refers to User?

Which is the best practice to refers Domain A to Domain B (ex. foreign key CompanyId inside User) to validate the data?

Thanks in advance!

CS