Merging the RFC as the agreed product contract for long-running-session assistant replies. Thank you @franksong2702! 🙏
It's docs-only (no code), well-structured, and gives the project a shared vocabulary for the follow-up implementation slices — in particular the honest terminal-state set (completed / cancelled / interrupted / compression-exhausted / tool-limit-reached / no-response / error, specific-wins-over-generic) and the live → settled → recovery/replay lifecycle. Nathan blessed merging it as the north-star contract.