fix(payment): 同时启用易支付和 Stripe 时显示 Stripe 按钮

VISIBLE_METHOD_ALIASES 漏了 stripe，导致 getVisibleMethods 把后端返回
的 stripe 过滤掉。点 Stripe 按钮时省略 method 查询参数，让落地页渲染
完整的 Payment Element。

frontend/src/components/payment/paymentFlow.ts

@@ -14,9 +14,10 @@ const VISIBLE_METHOD_ALIASES = {
   alipay_direct: 'alipay',
   wxpay: 'wxpay',
   wxpay_direct: 'wxpay',
+  stripe: 'stripe',
 } as const
 
-export type VisiblePaymentMethod = 'alipay' | 'wxpay'
+export type VisiblePaymentMethod = 'alipay' | 'wxpay' | 'stripe'
 export type StripeVisibleMethod = 'alipay' | 'wechat_pay'
 export type PaymentLaunchKind =
   | 'qr_waiting'
@@ -144,7 +145,12 @@ export function decidePaymentLaunch(
   }, context.now)
 
   if (baseState.clientSecret) {
-    const stripeMethod: StripeVisibleMethod = visibleMethod === 'wxpay' ? 'wechat_pay' : 'alipay'
+    // visibleMethod === 'stripe' means the user clicked the dedicated Stripe button
+    // and should land on the full Payment Element to choose a sub-method themselves.
+    const isStripeButton = visibleMethod === 'stripe'
+    const stripeMethod: StripeVisibleMethod | undefined = isStripeButton
+      ? undefined
+      : visibleMethod === 'wxpay' ? 'wechat_pay' : 'alipay'
     const kind: PaymentLaunchKind = stripeMethod === 'alipay' && !context.isMobile
       ? 'stripe_popup'
       : 'stripe_route'