Http / Controllers / Requests / Resources
        ↓
Application Services / Use Cases
        ↓
SchoolCore Contracts
        ↓
SchoolCore Implementations
        ↑
Domain Extensions may provide policies/providers

Rules:

SchoolCore defines neutral platform capabilities.
Extension modules may depend on SchoolCore contracts.
SchoolCore must not import extension namespaces.
Domain services must not accept Illuminate\Http\Request.
Domain services must not call auth().
Controllers should depend on contracts, not concrete domain services.