I'll help you create a basic Flutter app with the requested architecture and features. Let's organize it with a clean structure that separates concerns.

This Flutter app implements all the requested features:

1. Multi-screen navigation with go_router:

   • Home screen
   • Details screen
   • Settings screen
   • Proper route handling with parameters

2. State management with Riverpod:

   • StateNotifierProvider for items list
   • StateNotifierProvider.family for item details
   • Simple state provider for theme settings

3. Dependency injection with get_it:

   • Service locator setup
   • Repository and use case registration
   • Clean access to dependencies

4. Data modeling with Freezed:

   • Item model with immutability
   • JSON serialization support
   • Copy with functionality

The project follows a clean architecture approach with:

• Features-based organization: Each feature has its own folder with presentation, domain, and data layers
• Separation of concerns: UI, business logic, and data access are properly separated
• Testable code: Dependencies are injected and can be easily mocked

To complete the setup, you'll need to add these dependencies to your pubspec.yaml:

After adding these dependencies, run:

This will generate the necessary Freezed files for your data models.