feat(订单): 实现推荐奖励系统支持佣金和赠送天数两种模式

重构推荐奖励处理逻辑，新增支持根据配置选择佣金奖励或赠送天数奖励
修改Discount相关字段类型为float64以支持小数折扣
添加GiftDays配置项控制赠送天数
新增FindActiveSubscribe方法查询用户有效订阅

internal/model/subscribe/subscribe.go

@@ -71,8 +71,8 @@ func (s *Subscribe) BeforeUpdate(tx *gorm.DB) error {
 }
 
 type Discount struct {
-	Months   int64 `json:"months"`
-	Discount int64 `json:"discount"`
+	Months   int64   `json:"months"`
+	Discount float64 `json:"discount"`
 }
 
 type Group struct {

internal/model/user/model.go

@@ -77,6 +77,7 @@ type customUserLogicModel interface {
 	QueryUserSubscribe(ctx context.Context, userId int64, status ...int64) ([]*SubscribeDetails, error)
 	FindOneSubscribeDetailsById(ctx context.Context, id int64) (*SubscribeDetails, error)
 	FindOneUserSubscribe(ctx context.Context, id int64) (*SubscribeDetails, error)
+	FindActiveSubscribe(ctx context.Context, userId int64) (*Subscribe, error)
 	FindUsersSubscribeBySubscribeId(ctx context.Context, subscribeId int64) ([]*Subscribe, error)
 	UpdateUserSubscribeWithTraffic(ctx context.Context, id, download, upload int64, tx ...*gorm.DB) error
 	QueryResisterUserTotalByDate(ctx context.Context, date time.Time) (int64, error)

internal/model/user/subscribe.go

@@ -198,3 +198,24 @@ func (m *defaultUserModel) DeleteSubscribeById(ctx context.Context, id int64, tx
 func (m *defaultUserModel) ClearSubscribeCache(ctx context.Context, data ...*Subscribe) error {
 	return m.ClearSubscribeCacheByModels(ctx, data...)
 }
+
+// FindActiveSubscribe finds the user's active subscription
+func (m *defaultUserModel) FindActiveSubscribe(ctx context.Context, userId int64) (*Subscribe, error) {
+	var data Subscribe
+	err := m.QueryNoCacheCtx(ctx, &data, func(conn *gorm.DB, v interface{}) error {
+		now := time.Now()
+		return conn.Model(&Subscribe{}).
+			Where("user_id = ? AND status = ? AND expire_time > ?", userId, 1, now).
+			Order("expire_time DESC").
+			First(&data).Error
+	})
+	
+	if err != nil {
+		if err == gorm.ErrRecordNotFound {
+			return nil, nil
+		}
+		return nil, err
+	}
+	
+	return &data, nil
+}