-- Restore the documented $1 starter credit for existing user default keys.
-- Keep explicit admin/recharge limits intact, and never leave default user keys
-- with NULL max_cost because NULL is treated as unlimited by the proxy path.
UPDATE downstream_api_keys
SET max_cost = 1.0,
    updated_at = datetime('now')
WHERE user_id IS NOT NULL
  AND (max_cost IS NULL OR max_cost <= 0.0)
  AND (
      name LIKE '% 的默认密钥'
      OR name LIKE '% default key'
      OR key LIKE 'sk-user-%'
  );