feat: refactor payment handling to use direct backend redirect instead of API call

app/payment/[uuid]/page.js

@@ -14,24 +14,16 @@ export default function PaymentDetailsPage() {
     const [error, setError] = useState(null);
     const [paying, setPaying] = useState(false);
 
-    const handleRetryPayment = async () => {
+    const handleRetryPayment = () => {
         if (!payment?.appointment_uuid) return;
         setPaying(true);
-        try {
-            const res = await request.postAppointmentPayment({
-                appointment_uuid: payment.appointment_uuid,
-                gateway: payment.gateway || "mellat",
-                frontend_address: `${window.location.origin}/payment/result`,
-            });
-            const payUrl = res?.data?.pay_url;
-            if (payUrl) {
-                window.location.href = payUrl;
-            } else {
-                setPaying(false);
-            }
-        } catch {
-            setPaying(false);
-        }
+        // بدون XHR: ریدایرکت خالص به entry واحد پرداخت در بک‌اند.
+        const apiBase = process.env.NEXT_PUBLIC_API_URL;
+        const gateway = payment.gateway || "mellat";
+        const ret = encodeURIComponent(`${window.location.origin}/payment/result`);
+        window.location.href =
+            `${apiBase}/api/v1/payment/order/${payment.appointment_uuid}` +
+            `?gateway=${encodeURIComponent(gateway)}&return=${ret}`;
     };
 
     useEffect(() => {