* refactor: deprecate int32 * fix(db): reject legacy user quota schemas at startup * fix(quota): enforce wallet bounds and saturating billing conversions * fix(rate-limit): keep count*duration from wrapping int64 * fix: error message
EPay allows users to switch payment methods (e.g. wxpay→alipay) during checkout, causing callback rejection. Replace fragile blocklist guard with a PaymentProvider field on TopUp and SubscriptionOrder that identifies which gateway created the order.
rafactor: payment