feat(waffo): Waffo payment gateway integration with configurable methods

- Add Waffo payment SDK integration (waffo-go v1.3.1)
- Backend: webhook handler, pay endpoint, order lock race-condition fix
- Settings: full Waffo config (API keys, sandbox/prod, currency, pay methods)
- Frontend: Waffo payment buttons in topup page, admin settings panel
- i18n: Waffo-related translations for en/fr/ja/ru/vi/zh-TW

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

model/topup.go

@@ -12,15 +12,15 @@ import (
 )
 
 type TopUp struct {
-	Id            int     `json:"id"`
-	UserId        int     `json:"user_id" gorm:"index"`
-	Amount        int64   `json:"amount"`
-	Money         float64 `json:"money"`
-	TradeNo       string  `json:"trade_no" gorm:"unique;type:varchar(255);index"`
-	PaymentMethod string  `json:"payment_method" gorm:"type:varchar(50)"`
-	CreateTime    int64   `json:"create_time"`
-	CompleteTime  int64   `json:"complete_time"`
-	Status        string  `json:"status"`
+	Id               int     `json:"id"`
+	UserId           int     `json:"user_id" gorm:"index"`
+	Amount           int64   `json:"amount"`
+	Money            float64 `json:"money"`
+	TradeNo          string  `json:"trade_no" gorm:"unique;type:varchar(255);index"`
+	PaymentMethod    string  `json:"payment_method" gorm:"type:varchar(50)"`
+	CreateTime       int64   `json:"create_time"`
+	CompleteTime     int64   `json:"complete_time"`
+	Status           string  `json:"status"`
 }
 
 func (topUp *TopUp) Insert() error {
@@ -376,3 +376,62 @@ func RechargeCreem(referenceId string, customerEmail string, customerName string
 
 	return nil
 }
+
+func RechargeWaffo(tradeNo string) (err error) {
+	if tradeNo == "" {
+		return errors.New("未提供支付单号")
+	}
+
+	var quotaToAdd int
+	topUp := &TopUp{}
+
+	refCol := "`trade_no`"
+	if common.UsingPostgreSQL {
+		refCol = `"trade_no"`
+	}
+
+	err = DB.Transaction(func(tx *gorm.DB) error {
+		err := tx.Set("gorm:query_option", "FOR UPDATE").Where(refCol+" = ?", tradeNo).First(topUp).Error
+		if err != nil {
+			return errors.New("充值订单不存在")
+		}
+
+		if topUp.Status == common.TopUpStatusSuccess {
+			return nil // 幂等：已成功直接返回
+		}
+
+		if topUp.Status != common.TopUpStatusPending {
+			return errors.New("充值订单状态错误")
+		}
+
+		dAmount := decimal.NewFromInt(topUp.Amount)
+		dQuotaPerUnit := decimal.NewFromFloat(common.QuotaPerUnit)
+		quotaToAdd = int(dAmount.Mul(dQuotaPerUnit).IntPart())
+		if quotaToAdd <= 0 {
+			return errors.New("无效的充值额度")
+		}
+
+		topUp.CompleteTime = common.GetTimestamp()
+		topUp.Status = common.TopUpStatusSuccess
+		if err := tx.Save(topUp).Error; err != nil {
+			return err
+		}
+
+		if err := tx.Model(&User{}).Where("id = ?", topUp.UserId).Update("quota", gorm.Expr("quota + ?", quotaToAdd)).Error; err != nil {
+			return err
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		common.SysError("waffo topup failed: " + err.Error())
+		return errors.New("充值失败，请稍后重试")
+	}
+
+	if quotaToAdd > 0 {
+		RecordLog(topUp.UserId, LogTypeTopup, fmt.Sprintf("Waffo充值成功，充值额度: %v，支付金额: %.2f", logger.FormatQuota(quotaToAdd), topUp.Money))
+	}
+
+	return nil
+}