refactor: 调整项目结构为单向依赖

backend/internal/service/group.go

@@ -0,0 +1,48 @@
+package service
+
+import "time"
+
+type Group struct {
+	ID             int64
+	Name           string
+	Description    string
+	Platform       string
+	RateMultiplier float64
+	IsExclusive    bool
+	Status         string
+
+	SubscriptionType string
+	DailyLimitUSD    *float64
+	WeeklyLimitUSD   *float64
+	MonthlyLimitUSD  *float64
+
+	CreatedAt time.Time
+	UpdatedAt time.Time
+
+	AccountGroups []AccountGroup
+	AccountCount  int64
+}
+
+func (g *Group) IsActive() bool {
+	return g.Status == StatusActive
+}
+
+func (g *Group) IsSubscriptionType() bool {
+	return g.SubscriptionType == SubscriptionTypeSubscription
+}
+
+func (g *Group) IsFreeSubscription() bool {
+	return g.IsSubscriptionType() && g.RateMultiplier == 0
+}
+
+func (g *Group) HasDailyLimit() bool {
+	return g.DailyLimitUSD != nil && *g.DailyLimitUSD > 0
+}
+
+func (g *Group) HasWeeklyLimit() bool {
+	return g.WeeklyLimitUSD != nil && *g.WeeklyLimitUSD > 0
+}
+
+func (g *Group) HasMonthlyLimit() bool {
+	return g.MonthlyLimitUSD != nil && *g.MonthlyLimitUSD > 0
+}