Alipay payment-method setup returns 502 while card succeeds

Description

On the OpenCode console, the Go subscription page shows a banner:
"Reauthorize Alipay before Sep 30, 2026 to keep your Go subscription renewing."

Clicking Reauthorize Alipay does nothing — no redirect to Alipay — and the page only
shows the error "Failed to start Stripe setup."

Calling the underlying API directly shows the Alipay payment-method setup endpoint returns
502, while the exact same endpoint succeeds for card. This looks like a server-side
Stripe gateway failure specific to the alipay payment method type, so re-authorization is
impossible for affected users.

Plugins

No response

OpenCode version

1.18.31

Steps to reproduce

1. Sign in to the OpenCode console and open the Go / billing page.

2. Click Reauthorize Alipay in the banner.

3. Nothing happens (no redirect); the UI shows "Failed to start Stripe setup."
   Browser DevTools Console shows:

   POST https://opencode.ai/console/api/billing/payment-methods/stripe/setup-session 502 (Bad Gateway)

Direct API reproduction (same logged-in browser session):

POST https://opencode.ai/console/api/billing/payment-methods/stripe/setup-session
Headers: content-type: application/json, x-org-id: <org id>

Body {"returnTo":"billing","paymentMethodType":"alipay"}
-> 502 {"_tag":"BillingPaymentGatewayFailed","gateway":"stripe"}

Body {"returnTo":"billing","paymentMethodType":"card"}
-> 200 {"url":"https://checkout.stripe.com/c/pay/cs_live_..."}

Body {"returnTo":"billing","paymentMethodType":"wechat_pay"}
-> 200 {"url":"https://checkout.stripe.com/c/pay/cs_live_..."}

Screenshot and/or share link

No response

Operating System

Windows 11 (10.0.26100)

Terminal

No response

Start by reproducing the POST to /console/api/billing/payment-methods/stripe/setup-session with paymentMethodType set to alipay, then compare its server-side path with the successful card and wechat_pay requests. Trace the setup-session entry point and Stripe gateway response; done means Alipay setup returns a usable redirect URL and the Reauthorize Alipay action redirects instead of showing the 502 error.