## Summary
- carry the per-turn extension data through RunningTask so abort
handling can rebuild SessionTaskContext
- update stale test ExtensionData::new() callsites to pass the turn id
## Testing
- Not run after PR branch creation; CI will cover.
## Summary
- run registered TurnItemContributor hooks for parsed stream output
items
- plumb the active turn extension store into stream item handling
- preserve existing memory citation parsing as fallback after
contributors run
## Tests
- cargo test -p codex-core stream_events_utils -- --nocapture
- just fmt
- just fix -p codex-core
- git diff --check
Abhinav Vedmala