Stream Infinite Responses

Stream infinite context response in real-time using Server-Sent Events (SSE). This endpoint connects to the S2 StreamStore and streams the AI-generated response as it's being produced by the Lambda reducer function. Args: request_id: The unique identifier for the response request request: FastAPI request object for auth validation Returns: StreamingResponse with text/event-stream content Events: - data: Text chunks from the AI response - complete: Final event with metadata when stream finishes - error: Error event if streaming fails