-- t-paliad-235: track aichat conversation id on each paliadin turn so the
-- recovery endpoint can ask aichat for the late-arriving response when
-- paliad's stream connection drops mid-turn.
--
-- The PALIADIN_BACKEND=aichat path persists this from the upstream
-- /chat/turn/stream `done` frame's conversation_id. PALIADIN_BACKEND=legacy
-- turns leave it NULL — the filesystem janitor is still the recovery path
-- there.

ALTER TABLE paliad.paliadin_turns
  ADD COLUMN IF NOT EXISTS aichat_conversation_id uuid;

COMMENT ON COLUMN paliad.paliadin_turns.aichat_conversation_id IS
  'Aichat backend conversation id (t-paliad-235). Set when the streaming /chat/turn/stream done frame arrives, or when the recovery endpoint asks aichat to disambiguate which conversation this turn lives in. NULL for legacy backend turns and for aichat turns that errored before the conversation id was resolved.';
