优化平台运营概览并对齐管理端布局

统一管理端侧栏与顶栏 56px 高度；运营概览按 P2-08 重做 KPI、增长趋势、套餐分布与操作日志。

server/internal/handler/admin.go

@@ -17,32 +17,50 @@ type AdminHandler struct{}
 func NewAdminHandler() *AdminHandler { return &AdminHandler{} }
 
 func (h *AdminHandler) Stats(c *gin.Context) {
-	var tenantTotal, activeTotal, suspendedTotal, expiringTotal int64
+	var tenantTotal, activeTotal, suspendedTotal, expiringTotal, newThisMonth int64
 
 	model.DB.Model(&model.Tenant{}).Count(&tenantTotal)
 	model.DB.Model(&model.Tenant{}).Where("status = ?", "normal").Count(&activeTotal)
 	model.DB.Model(&model.Tenant{}).Where("status = ?", "suspended").Count(&suspendedTotal)
 	model.DB.Model(&model.Tenant{}).Where("status = ?", "expiring").Count(&expiringTotal)
 
+	now := time.Now()
+	monthStart := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
+	model.DB.Model(&model.Tenant{}).Where("created_at >= ?", monthStart).Count(&newThisMonth)
+
 	// 估算月收入：正常/即将到期租户 × 套餐月费
 	type planCount struct {
 		PlanID uint
 		Count  int64
 	}
-	var counts []planCount
+	var incomeCounts []planCount
 	model.DB.Model(&model.Tenant{}).
 		Select("plan_id, count(*) as count").
 		Where("status IN ? AND plan_id IS NOT NULL", []string{"normal", "expiring"}).
 		Group("plan_id").
-		Scan(&counts)
+		Scan(&incomeCounts)
 	var monthlyIncome int64
-	planDist := make([]gin.H, 0)
-	for _, item := range counts {
+	for _, item := range incomeCounts {
 		var plan model.Plan
 		if err := model.DB.First(&plan, item.PlanID).Error; err != nil {
 			continue
 		}
 		monthlyIncome += int64(plan.PriceMonthly) * item.Count
+	}
+
+	// 套餐分布：全部已绑定套餐的租户
+	var distCounts []planCount
+	model.DB.Model(&model.Tenant{}).
+		Select("plan_id, count(*) as count").
+		Where("plan_id IS NOT NULL").
+		Group("plan_id").
+		Scan(&distCounts)
+	planDist := make([]gin.H, 0, len(distCounts))
+	for _, item := range distCounts {
+		var plan model.Plan
+		if err := model.DB.First(&plan, item.PlanID).Error; err != nil {
+			continue
+		}
 		planDist = append(planDist, gin.H{
 			"plan_id": plan.ID,
 			"name":    plan.Name,
@@ -50,18 +68,36 @@ func (h *AdminHandler) Stats(c *gin.Context) {
 		})
 	}
 
+	// 近 6 个月租户增长
+	growth := make([]gin.H, 0, 6)
+	for offset := 5; offset >= 0; offset-- {
+		mStart := time.Date(now.Year(), now.Month()-time.Month(offset), 1, 0, 0, 0, 0, now.Location())
+		mEnd := mStart.AddDate(0, 1, 0)
+		var newCnt, totalCnt int64
+		model.DB.Model(&model.Tenant{}).Where("created_at >= ? AND created_at < ?", mStart, mEnd).Count(&newCnt)
+		model.DB.Model(&model.Tenant{}).Where("created_at < ?", mEnd).Count(&totalCnt)
+		growth = append(growth, gin.H{
+			"month":      mStart.Format("1月"),
+			"month_key":  mStart.Format("2006-01"),
+			"new_count":  newCnt,
+			"total_count": totalCnt,
+		})
+	}
+
 	var recentLogs []model.OperationLog
-	model.DB.Order("created_at desc").Limit(10).Find(&recentLogs)
+	model.DB.Order("created_at desc").Limit(12).Find(&recentLogs)
 
 	middleware.JSON(c, gin.H{
-		"tenant_total":     tenantTotal,
-		"active_tenant":    activeTotal,
-		"suspended_tenant": suspendedTotal,
-		"expiring_tenant":  expiringTotal,
-		"monthly_income":   monthlyIncome,
-		"system_uptime":    "99.95%",
-		"plan_distribution": planDist,
-		"recent_logs":      recentLogs,
+		"tenant_total":       tenantTotal,
+		"active_tenant":      activeTotal,
+		"suspended_tenant":   suspendedTotal,
+		"expiring_tenant":    expiringTotal,
+		"new_tenants_month":  newThisMonth,
+		"monthly_income":     monthlyIncome,
+		"system_uptime":      "99.95%",
+		"plan_distribution":  planDist,
+		"tenant_growth":      growth,
+		"recent_logs":        recentLogs,
 	})
 }