handle_create

Drive the graph and yield Responses API events.

Override this when wholesale customisation is needed. By default the method:

 1. emits ``response.created`` / ``response.in_progress`` and durably
     checkpoints handler admission,
        2. resolves the LangGraph thread and checks for pending
         ``interrupt()`` pauses on the checkpointed

thread and:

• if the request contains an mcp_approval_response with approve=false for a pending interrupt, emits response.failed(code="interrupt_rejected", …) and stops;
• otherwise tries to resume from a matching function_call_output (rich) or mcp_approval_response{approve:true} (echo the interrupt value back),

3. drives the graph via :meth:CompiledStateGraph.astream or :meth:CompiledStateGraph.ainvoke depending on request.stream,
4. emits the resulting output items, surfacing any new pending interrupts as a pair of function_call + mcp_approval_request items both keyed by the LangGraph interrupt id, and
5. emits response.completed (or response.failed / response.cancelled on error).