feat(payment): show order status page after EasyPay redirect payment

- After opening pay_url in new window, navigate to order status page
  with countdown timer and order polling (reuses QRCode view)
- QRCode view now shows "pay in new window" UI when no QR code present
- Add verbose logging for webhook signature verification failures

backend/cmd/server/VERSION

@@ -1 +1 @@
-0.1.108.77
+0.1.108.78

backend/internal/handler/payment_webhook_handler.go

@@ -83,7 +83,7 @@ func (h *PaymentWebhookHandler) handleNotify(c *gin.Context, providerKey string)
 
 	notification, err := provider.VerifyNotification(c.Request.Context(), rawBody, headers)
 	if err != nil {
-		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err)
+		slog.Error("[Payment Webhook] verify failed", "provider", providerKey, "error", err, "method", c.Request.Method, "rawBody", rawBody)
 		c.String(http.StatusBadRequest, "verify failed")
 		return
 	}

frontend/src/i18n/locales/en.ts

@@ -5095,6 +5095,9 @@ export default {
     },
     qr: {
       scanToPay: 'Scan to Pay',
+      payInNewWindow: 'Complete Payment in New Window',
+      payInNewWindowHint: 'The payment page has opened in a new window. Please complete the payment there and return to this page.',
+      openPayWindow: 'Reopen Payment Page',
       expiresIn: 'Expires in',
       expired: 'Order Expired',
       waitingPayment: 'Waiting for payment...',

frontend/src/i18n/locales/zh.ts

@@ -5292,6 +5292,9 @@ export default {
     },
     qr: {
       scanToPay: '请扫码支付',
+      payInNewWindow: '请在新窗口中完成支付',
+      payInNewWindowHint: '支付页面已在新窗口打开，请在新窗口中完成支付后返回此页面',
+      openPayWindow: '重新打开支付页面',
       expiresIn: '剩余支付时间',
       expired: '订单已过期',
       waitingPayment: '等待支付...',

frontend/src/views/user/PaymentQRCodeView.vue

@@ -1,10 +1,19 @@
 <template>
   <AppLayout>
     <div class="mx-auto flex max-w-md flex-col items-center space-y-6 py-8">
-      <h2 class="text-xl font-semibold text-gray-900 dark:text-white">{{ t('payment.qr.scanToPay') }}</h2>
+      <h2 class="text-xl font-semibold text-gray-900 dark:text-white">
+        {{ qrUrl ? t('payment.qr.scanToPay') : t('payment.qr.payInNewWindow') }}
+      </h2>
       <div v-if="qrUrl" class="rounded-2xl bg-white p-6 shadow-lg dark:bg-dark-800">
         <canvas ref="qrCanvas" class="mx-auto"></canvas>
       </div>
+      <div v-else-if="payUrl && !expired" class="w-full space-y-3 text-center">
+        <p class="text-sm text-gray-500 dark:text-gray-400">{{ t('payment.qr.payInNewWindowHint') }}</p>
+        <a :href="payUrl" target="_blank" rel="noopener noreferrer"
+          class="btn btn-primary inline-flex w-full items-center justify-center gap-2 py-3">
+          {{ t('payment.qr.openPayWindow') }}
+        </a>
+      </div>
       <div v-if="expired" class="text-center">
         <p class="text-lg font-medium text-red-500">{{ t('payment.qr.expired') }}</p>
         <button class="btn btn-primary mt-4" @click="router.push('/purchase')">{{ t('payment.result.backToRecharge') }}</button>
@@ -41,6 +50,7 @@ const appStore = useAppStore()
 
 const qrCanvas = ref<HTMLCanvasElement | null>(null)
 const qrUrl = ref('')
+const payUrl = ref('')
 const orderId = ref(0)
 const remainingSeconds = ref(0)
 const expired = ref(false)
@@ -114,6 +124,7 @@ watch(qrUrl, () => renderQR())
 onMounted(() => {
   orderId.value = Number(route.query.order_id) || 0
   qrUrl.value = (route.query.qr as string) || ''
+  payUrl.value = (route.query.pay_url as string) || ''
 
   // Calculate countdown from expiresAt
   const expiresAtStr = route.query.expires_at as string

frontend/src/views/user/PaymentView.vue

@@ -236,6 +236,7 @@ async function createOrder(orderAmount: number, orderType: string, planId?: numb
       router.push({ path: '/payment/qrcode', query: { order_id: String(result.order_id), qr: result.qr_code || '', pay_url: result.pay_url || '', expires_at: result.expires_at || '' } })
     } else if (result.pay_url) {
       window.open(result.pay_url, '_blank')
+      router.push({ path: '/payment/qrcode', query: { order_id: String(result.order_id), pay_url: result.pay_url, expires_at: result.expires_at || '' } })
     } else {
       errorMessage.value = t('payment.result.failed')
       appStore.showError(errorMessage.value)