Typed shape of the data column: the session's durable continuity state.
Stored in the existing data JSON column (no dedicated columns) — every field is read and compared in the runner, never queried server-side, so a typed DTO gives the contract without a schema change.
Remote sandbox id to record alongside the continuity state.
the writer's conversation turn index; the pointer write is applied only when it is >= the row's data.latest_turn_index.
Successful Response