- Create ProfileWorker namespace with 4 separate components
- ProfileWorker.cs: BackgroundService orchestrator with IOptions support
- ProfileWorkerOptions.cs: Configuration model with validation
- ProfileCache.cs: Thread-safe cache using composition pattern
- DependencyInjection.cs: Service registration with IValidateOptions
Benefits:
- Separation of concerns (orchestration, config, state, DI)
- IOptions pattern for appsettings.json configuration
- Startup validation for configuration errors
- Better testability and maintainability