Extend taskrun executors to return full TaskRunResult, finalize assistant placeholder content with artifact metadata, and map quality_failed terminal state instead of metadata-only updates. Co-authored-by: Cursor <cursoragent@cursor.com>
Add POST/GET/POST cancel task run APIs, background worker with event replay, workspace reconcile, runner child cancel, and chat message metadata updates. Co-authored-by: Cursor <cursoragent@cursor.com>