Design the Layer Structure

Background: I've chosen [architecture, e.g. MVVM + Clean] for my native
[platform] app using [SwiftUI+Combine / Compose]. The app's main
features are: [list].

Use case: Define the concrete layer structure—what lives where and the
rules for what each layer is allowed to depend on.

Implementation details:
- Presentation, domain/business logic, and data layers at minimum
- Specify the dependency direction (which layer may import which)
- Show where reactive types live (Combine publishers / Kotlin Flow) and
  where they get converted to view state
- Define how the UI talks to logic (view model interface) and how logic
  talks to data (repository interface)

Layer & dependencies: Dependencies should point inward—UI depends on
domain, domain depends on nothing platform-specific. Flag any place my
plan would violate that.

Deliverable: A layer diagram (text), the responsibility of each layer,
the allowed-dependency rules, and a worked example tracing one feature
(e.g., "load profile") from view down to data and back.