ActivityHandler
dart
abstract interface class ActivityHandler<I, O> {
Future<O> handle(ActivityContext context, I input);
}ActivityHandler.from((context, input) async => ...) is the function form. Bind handlers in a WorkflowModule with ActivityBinding.from.
ActivityContext provides:
runId,commandId,operationKey,attemptidempotencyKeyheartbeat()
Graph TaskExecutor and TaskSuccess / TaskFailure effects are legacy.