-- BUG-991: put archived sessions back on the live list.
-- Keep archived_at for a later drop (AGENTS.md §7.6). Do not bump updated_at
-- (BUG-988). Idempotent: a second run matches 0 rows.

begin;

do $migration$
begin
  if current_user <> 'schema_owner' then
    raise exception 'retire_chat_session_archive_requires_schema_owner'
      using errcode = '42501';
  end if;
end
$migration$;

update public.chat_sessions
set archived_at = null
where archived_at is not null;

commit;