0002: Capture and replay have separate data responsibilities¶

Status: implementation backfill. This records the existing contract without inferring independent maintainer approval.

Context. Running tasks, recording model traffic, and restoring native agent context require different protocols and dependencies.

Options. Put every protocol in the execution core, or exchange explicit records across independent components.

Current choice. Gateway owns model traffic capture and routing; Replay consumes native agent trajectories and re-executes tools; the execution core maintains Run lifecycle and shared records. Gateway is an optional feature, and Replay has a separate crate and command. See Replay design.

Consequences. Users can use execution and staging alone. Capture journals and native trajectories must be collected separately; new agent integrations primarily belong in the Replay adapter boundary.