android-kmp-architecturelisted

# CIEL ADAPTATION: Android & KMP Architecture (Structural Layer) This skill formalizes the "Structural Layer" for Android and KMP projects. It enforces module isolation and dependency inversion to ensure cross-platform portability and testability. ## Recommended Module Layout ```text project/ ├── app/ # Platform entry point (Android), DI wiring. ├── domain/ # Pure Kotlin. UseCases, Domain Models, Repository Interfaces. ├── data/ # Repository Impls, DataSources (Room/SQLDelight), Network (Ktor). ├── presentation/ # ViewModels, UI State, Flow collection. └── core/ # Shared utilities, error types, base classes. ``` ## Dependency Rules (Immutable) 1. **Domain Isolation**: `domain` MUST NEVER depend on `data`, `presentation`, or any platform framework. 2. **One-Way Flow**: `app` -> `presentation` -> `domain` <- `data`. 3. **Mappers**: Keep mappers (e.g., `Entity -> Domain`) as extension functions in the `data` layer. ## Core Patterns - **UseCase**: Single business operation. Use `operator fun invoke` for clean call sites. - **Result/Try**: Use a sealed interface (e.g., `Result<T>`) for all repository/use-case returns to avoid unchecked exceptions. - **DI**: Standardize on Koin (KMP-friendly) or Hilt (Android-only). ## Anti-Patterns - **Context Leaking**: Passing Android `Context` or framework classes into the `domain` layer. - **Fat ViewModels**: Putting business logic in ViewModels instead of UseCases