Automatic Reactivity - render() now automatically tracks reactive dependencies

• No more manual watchEffect + rebuild() needed in setup()
• Accessing Ref.value or Computed.value in render() auto-triggers rebuilds when they change
• Similar to Vue's template reactivity

Removed rebuild() method - No longer needed with automatic tracking

• count() is now equivalent to count.value
• Strongly typed watch() API with proper type inference

Component Base Class (src/component/)

• Vue-like Component extending StatefulWidget
• setup() method for reactive state initialization
• render() method replacing build()
• rebuild() method to trigger component update

Lifecycle Hooks (src/component/lifecycle.dart)

• onBeforeMount - Before first build
• onMounted - After first build
• onBeforeUpdate - Before rebuild
• onUpdated - After rebuild
• onBeforeUnmount - Before dispose
• onUnmounted - After dispose
• onErrorCaptured - Error boundary
• onActivated / onDeactivated - Route visibility
• onRenderTracked / onRenderTriggered - Debug hooks

Dependency Injection (src/di/service_locator.dart)

• register<T>() - Register singleton
• registerFactory<T>() - Register factory
• get<T>() - Get instance
• isRegistered<T>() - Check registration
• unregister<T>() - Remove registration
• resetServiceLocator() - Clear all