fix: 增强BepUsdt钱包地址获取逻辑

- 尝试多个可能的字段名获取钱包地址
- 如果没有直接返回，尝试从payment_url解析
- 添加详细日志记录

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/api/handlers/payment.go

@@ -156,7 +156,37 @@ func (h *PaymentHandler) CreatePayment(c *gin.Context) {
 	tradeID, _ := data["trade_id"].(string)
 	token, _ := data["token"].(string)
 	paymentURL, _ := data["payment_url"].(string)
-	walletAddress, _ := data["address"].(string)
+
+	// 尝试多个可能的字段名获取钱包地址
+	var walletAddress string
+	addressFields := []string{"address", "wallet_address", "to_address", "payment_address", "deposit_address", "receiver_address"}
+	for _, field := range addressFields {
+		if addr, ok := data[field].(string); ok && addr != "" {
+			walletAddress = addr
+			log.Printf("[BepUsdt] found wallet address in field '%s': %s", field, addr)
+			break
+		}
+	}
+
+	// 如果没有直接获取到钱包地址，尝试从payment_url解析
+	if walletAddress == "" && paymentURL != "" {
+		// payment_url格式可能是: usdt:TRC20地址?amount=xxx 或直接是钱包地址
+		if strings.HasPrefix(paymentURL, "usdt:") || strings.HasPrefix(paymentURL, "USDT:") {
+			parts := strings.SplitN(paymentURL, ":", 2)
+			if len(parts) > 1 {
+				// 移除查询参数
+				addrPart := strings.SplitN(parts[1], "?", 2)[0]
+				walletAddress = strings.TrimSpace(addrPart)
+				log.Printf("[BepUsdt] parsed wallet address from payment_url: %s", walletAddress)
+			}
+		} else if len(paymentURL) >= 30 && !strings.Contains(paymentURL, "://") {
+			// 可能直接就是钱包地址
+			walletAddress = paymentURL
+			log.Printf("[BepUsdt] using payment_url as wallet address: %s", walletAddress)
+		}
+	}
+
+	log.Printf("[BepUsdt] payment data: trade_id=%s, token=%s, payment_url=%s, wallet_address=%s", tradeID, token, paymentURL, walletAddress)
 
 	var amount float64
 	if v, ok := data["amount"].(float64); ok {