fix(payment): re-pay with fresh provider out_trade_no

WeChat/Alipay/Epay reject reusing the same merchant order number when
params change. Allocate attempt-suffixed out_trade_no on resume pay,
map callbacks back to the local order, and best-effort close prior trades.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AKSRT/Shop/CheckoutService.php

@@ -226,6 +226,28 @@ class CheckoutService {
             return $this->pay_with_points($user_id, $order_number, $order);
         }
 
+        // External gateways: allocate a fresh out_trade_no so re-pay works when
+        // the provider rejects "same order number with changed params".
+        $needs_attempt = !in_array($payment_method, ['balance', 'points'], true);
+        if ($needs_attempt && class_exists('\AKSRT\Payment\OrderRepository')) {
+            $attempt = $repo->allocate_payment_attempt($order_number);
+            if ($attempt === null) {
+                return ['success' => false, 'message' => __('无法生成支付单号，请稍后重试。', 'aksrt')];
+            }
+            $order = $repo->get_user_order($user_id, $order_number) ?: $order;
+            $order['out_trade_no'] = (string) $attempt['out_trade_no'];
+            // Close previous provider trade when possible (WeChat/Alipay) so the new attempt is clean.
+            if (!empty($attempt['previous'])
+                && $attempt['previous'] !== $attempt['out_trade_no']
+                && method_exists($gateway, 'close_trade')) {
+                try {
+                    $gateway->close_trade((string) $attempt['previous']);
+                } catch (\Throwable $e) {
+                    // best-effort
+                }
+            }
+        }
+
         $payment_result = $gateway->create_payment($order);
         if (empty($payment_result['success'])) {
             return ['success' => false, 'message' => $payment_result['message'] ?? __('支付失败。', 'aksrt')];