feat: CLAUDE.md重写;修复Dashboard GetMetrics假数据改为真实AgentReport;审批流程完整验证通过;移除AlertManager静默规则占位Tab

backend/internal/api/handlers/dashboard.go

@@ -279,7 +279,7 @@ func (h *DashboardHandler) GetRecentReleases(c *gin.Context) {
 
 // GetMetrics 获取监控指标
 // @Summary 获取监控指标
-// @Description 获取系统监控指标数据
+// @Description 获取系统监控指标数据（基于 AgentReport 真实数据）
 // @Tags 仪表盘
 // @Produce json
 // @Security Bearer
@@ -288,28 +288,38 @@ func (h *DashboardHandler) GetRecentReleases(c *gin.Context) {
 // @Router /dashboard/metrics [get]
 func (h *DashboardHandler) GetMetrics(c *gin.Context) {
 	hours := 24
+	if hv := c.Query("hours"); hv != "" {
+		if parsed, err := strconv.Atoi(hv); err == nil && parsed > 0 && parsed <= 168 {
+			hours = parsed
+		}
+	}
+
+	// 从 agent_reports 表查最近 N 小时的真实数据
+	since := time.Now().Add(-time.Duration(hours) * time.Hour)
+	type avgPoint struct {
+		Bucket   time.Time
+		AvgCPU   float64
+		AvgMem   float64
+	}
+	var rows []avgPoint
+	h.db.Model(&models.AgentReport{}).
+		Select("strftime('%Y-%m-%d %H:00', created_at) as bucket, AVG(cpu_usage) as avg_cpu, AVG(mem_usage) as avg_mem").
+		Where("created_at >= ?", since).
+		Group("bucket").
+		Order("bucket ASC").
+		Scan(&rows)
 
-	// 生成模拟数据
 	var metrics []models.MetricData
-	now := time.Now()
+	for _, r := range rows {
+		metrics = append(metrics,
+			models.MetricData{Name: "cpu", Value: r.AvgCPU, Timestamp: r.Bucket},
+			models.MetricData{Name: "memory", Value: r.AvgMem, Timestamp: r.Bucket},
+		)
+	}
 
-	for i := 0; i < hours; i++ {
-		timestamp := now.Add(-time.Duration(hours-i) * time.Hour)
-		metrics = append(metrics, models.MetricData{
-			Name:      "cpu",
-			Value:     40 + float64(i%30),
-			Timestamp: timestamp,
-		})
-		metrics = append(metrics, models.MetricData{
-			Name:      "memory",
-			Value:     50 + float64(i%20),
-			Timestamp: timestamp,
-		})
-		metrics = append(metrics, models.MetricData{
-			Name:      "disk",
-			Value:     45 + float64(i%10),
-			Timestamp: timestamp,
-		})
+	// 如果没有真实数据，返回空数组（不造假数据）
+	if metrics == nil {
+		metrics = []models.MetricData{}
 	}
 
 	c.JSON(http.StatusOK, models.Response{