Creates an OrchestratorFactory with async initialization.
This is the recommended way to create an OrchestratorFactory as it properly initializes all async dependencies like the WorkflowEngine.
Optionalconfig: OrchestratorFactoryConfigFactory configuration
Promise resolving to initialized OrchestratorFactory
Orchestration exports - Factory, graph workflows, and spec-driven execution Split from index.ts for file size compliance (Issue #285)