Presentation and runtime context

FlutterErrorBuildMode.detect() maps Flutter compile-time constants to debug, profile, or release. FlutterErrorBuildMode.environment(...) combines that result with an explicit deployment target and application identity.

FlutterRuntimeErrorContextProvider adds bounded facts: target platform, web flag, lifecycle state, locale list, platform brightness, Flutter library and operation context, and the silent diagnostics flag. It does not collect widget trees, route arguments, input values, or arbitrary diagnostics.

Application-defined presentation

NavigatorErrorPresenter obtains the current root navigation context from an application-owned GlobalKey<NavigatorState> and calls FlutterErrorPresentationDelegate.

@override
Future<void> present(
  BuildContext? context,
  ErrorIncident incident,
  ErrorPresentationDirective directive,
) async {
  if (context == null || directive == ErrorPresentationDirective.none) return;
  // Choose Material, Cupertino, navigation, or another app-specific UI.
}

The package does not impose dialogs, SnackBars, routes, wording, or visual style. The delegate must tolerate a null context during startup and shutdown.