Clearer run behavior: Streaming flags no longer persist

To make runs more predictable, the stream and stream_events flags no longer persist across run/arun calls. This eliminates hidden state between invocations and ensures teams explicitly control streaming behavior per execution, improving reproducibility in development and production.

Details

Set streaming flags on each run/arun to opt in per execution
Reduces surprises and aligns runs across services and environments

Who this is for: Platform owners and teams standardizing run behavior in production pipelines and multi-service deployments.