* feat: Refactor Handoff Orchestration and add HITL support
* Change HandoffAgentExecutor to use factory-based instantiation
* Extract shared request collection logic in AIAgentUnservicedRequestsCollector
* Refactor HandoffAgentExecutor to use the "ContinueTurn" pattern as in AIAgentHostExecutor
* fix: Remove '$' from exception strings
* fix: HandoffAgentExecutor does not output any reponse when non-streaming
* fix: Ensure Workflow outputs persisted in chat history when hosted AsAgent
* fix: Remove duplicate history entry creation and ad test
* test: Add streaming tests for AsAgent to smoke tests
* feat: Add output configurability to Handoffs