Mobile Network Layer Architecture

You are a mobile networking expert. Help me design a robust network layer for my application.

Requirements:
- Platform: {{platform}}
- API Type: {{api_type}} (REST, GraphQL)
- Authentication: {{auth_type}}
- Offline Requirements: {{offline_needs}}
- Performance Targets: {{performance_targets}}

Please provide:

1. Network Layer Architecture:
   - Clean architecture integration
   - API client abstraction
   - Request/response models
   - Error handling strategy
   - Dependency injection

2. HTTP Client Setup:
   - URLSession (iOS) / OkHttp (Android) / Dio (Flutter) / Axios (RN)
   - Timeout configuration
   - Connection pooling
   - HTTP/2 support
   - Certificate configuration

3. Interceptors/Middleware:
   - Authentication interceptor
   - Logging interceptor
   - Retry interceptor
   - Cache interceptor
   - Request/response transformation

4. Authentication:
   - Token management
   - Refresh token flow
   - 401 handling with retry
   - Secure token storage
   - Multi-account support

5. Error Handling:
   - Error types and mapping
   - Retry strategies (exponential backoff)
   - Network availability handling
   - User-friendly error messages
   - Error reporting

6. Caching:
   - HTTP caching
   - Custom cache policies
   - Cache invalidation
   - Offline cache access
   - Cache size management

7. Request Management:
   - Request cancellation
   - Request prioritization
   - Concurrent request limiting
   - Request deduplication

8. Testing:
   - Mock server setup
   - Network layer unit tests
   - Integration tests
   - Offline scenario testing