Successful Response
Per-chat token + cost totals, summed across the session's messages.
Daily org spend-budget snapshot for the client's soft-warning banner.
near_limit is set once spend crosses ask_feather_daily_org_budget_alert_ratio of the budget; reset_at is epoch seconds of the next UTC midnight.
The session's current in-flight turn, so a client that lost its turn_id (page refresh, new tab, dropped connection) can rediscover it and re-subscribe to …/turns/{turn_id}/stream (ENG-860 Phase 4). None on session-detail when the latest turn is terminal (nothing to reconnect to).