描述
Design, refactor, review, or implement Flutter app architecture using MVVM, layered UI/Data/optional Domain boundaries, feature-first or layer-first project structure, repositories, services, dependency injection, Result and Command patterns, offline-first or optimistic UI flows. Use when asked to add a Flutter feature, audit layer dependencies, fix cross-feature imports, migrate to feature-first, choose architecture for a Flutter project, or create scalable maintainable Flutter code organization.