Back MAF's opt-in AG-UI snapshot persistence with a DB store so the
conversation survives page reloads and restarts:
- ChatThreadSnapshot: one upserted row per (scope, thread_id), JSONB
messages/state/interrupt (migration 794baf50635b)
- PostgresSnapshotStore implements the AGUIThreadSnapshotStore protocol.
It opens its own sessions (MAF saves during SSE streaming, after the
request middleware has closed the ContextVar session) and sanitizes on
save: camelCase toolCalls/toolCallId (the @ag-ui/client Zod schema
strips snake_case, which would lose cards on replay), drop BFF ctx-*
context messages, dedupe MAF's re-recorded multi-run turns, and drop
orphaned tool results
- Endpoint mount gains snapshot_store + a constant scope resolver
(single-user app; auth already enforced by agent_auth_and_session)
- DELETE /api/v1/chat/thread resets the conversation
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
