[Producer] Upstream Bug – Provide reliable cancel/abort for in-progress task #57
Description
Context
Mirrors upstream bug: openai#1215
Users cannot reliably stop an in-progress task once started.
Acceptance Criteria
- Provide a clear UX to cancel/abort the active run (keyboard shortcut and command)
- Ensure cleanup of child processes and background tasks
- Confirm no dangling approvals or partial edits post-abort
- Add tests for abort semantics in interactive and non-interactive modes
Refs: #6, upstream: openai#1215