revert(payment): remove unsupported Stripe and EzPay upgrade

src/lib/payment/payment_launch.ts

@@ -143,27 +143,6 @@ export function getStripeClientSecret(
   return null;
 }
 
-export function getStripeCustomerSessionClientSecret(
-  payParams: Record<string, unknown>,
-): string | null {
-  const provider = payParams.provider;
-  const isStripeProvider =
-    typeof provider !== "string" || provider.toLowerCase() === "stripe";
-  const enabled = payParams.savedPaymentMethodsEnabled === true;
-  const clientSecret = payParams.customerSessionClientSecret;
-
-  if (
-    isStripeProvider &&
-    enabled &&
-    typeof clientSecret === "string" &&
-    /^cuss_[^\s]+_secret_[^\s]+$/i.test(clientSecret)
-  ) {
-    return clientSecret;
-  }
-
-  return null;
-}
-
 export interface LaunchEzpayRedirectInput {
   orderId: string | null;
   paymentUrl: string;