feat(k8s): M1 SyncCluster 增加 metrics 采集

后端:
- SyncCluster 中调 GetNodeMetrics() 获取 metrics-server 数据
- 节点 INSERT 增加 cpu_usage/memory_usage 百分比字段
- 新增 parseCpuNanoToMilli / parseMemKiToMi 辅助函数
- 采集 Pod metrics（为 M2 准备）

前端:
- KubernetesClusterDetail 删除硬编码 resourceData mock
- 改为从节点 metrics 实时计算集群 CPU/内存使用率
- 图表 Y 轴固定 0-100 域，底部显示百分比数值

新增文档:
- ROADMAP.md / TDD_PLAN.md / PROJECT_EVALUATION.md

backend/internal/api/handlers/kubernetes.go

@@ -647,6 +647,24 @@ func (h *KubernetesHandler) SyncCluster(c *gin.Context) {
 
 	result := k8sclient.SyncResult{}
 
+	// Fetch node metrics (best-effort — metrics-server may not be installed) // Logan.Li
+	nodeMetrics := map[string]k8sclient.NodeMetricsItem{}
+	if m, err := client.GetNodeMetrics(); err == nil {
+		for _, item := range m.Items {
+			nodeMetrics[item.Metadata.Name] = item
+		}
+	} else {
+		log.Printf("[K8s] sync: GetNodeMetrics failed (metrics-server not installed?): %v", err)
+	}
+
+	// Fetch pod metrics (best-effort) // Logan.Li
+	podMetrics := map[string]k8sclient.PodMetricsItem{} // key: "namespace/podname"
+	if pm, err := client.ListPodMetrics(""); err == nil {
+		for _, item := range pm.Items {
+			podMetrics[item.Metadata.Namespace+"/"+item.Metadata.Name] = item
+		}
+	}
+
 	// Sync nodes
 	if nodes, err := client.ListNodes(); err == nil {
 		// Use raw SQL for reliability (avoid GORM soft-delete / auto-timestamp issues)
@@ -674,10 +692,24 @@ func (h *KubernetesHandler) SyncCluster(c *gin.Context) {
 			}
 			labelsJSON, _ := json.Marshal(n.Metadata.Labels)
 			now := time.Now()
-			err2 := h.db.Exec(`INSERT INTO kubernetes_nodes (cluster_id, name, ip, role, status, os, kubelet_version, cpu, memory, max_pods, labels, created_at, updated_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+			// Compute CPU/memory usage percentage from metrics-server data // Logan.Li
+			cpuUsagePct, memUsagePct := 0.0, 0.0
+			if m, ok := nodeMetrics[n.Metadata.Name]; ok {
+				cpuCores := parseIntResource(n.Status.Capacity["cpu"])
+				memMB := parseMemResource(n.Status.Capacity["memory"])
+				if cpuCores > 0 {
+					cpuMillicores := parseCpuNanoToMilli(m.Usage["cpu"])
+					cpuUsagePct = float64(cpuMillicores) / float64(cpuCores*1000) * 100
+				}
+				if memMB > 0 {
+					memMi := parseMemKiToMi(m.Usage["memory"])
+					memUsagePct = float64(memMi) / float64(memMB) * 100
+				}
+			}
+			err2 := h.db.Exec(`INSERT INTO kubernetes_nodes (cluster_id, name, ip, role, status, os, kubelet_version, cpu, memory, max_pods, cpu_usage, memory_usage, labels, created_at, updated_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
 				cluster.ID, n.Metadata.Name, ip, role, nodeStatus, n.Status.NodeInfo.OSImage, n.Status.NodeInfo.KubeletVersion,
 				parseIntResource(n.Status.Capacity["cpu"]), parseMemResource(n.Status.Capacity["memory"]), parseIntResource(n.Status.Capacity["pods"]),
-				string(labelsJSON), now, now).Error
+				cpuUsagePct, memUsagePct, string(labelsJSON), now, now).Error
 			if err2 != nil {
 				log.Printf("[K8s] insert node %s error: %v", n.Metadata.Name, err2)
 			} else {
@@ -1928,6 +1960,17 @@ func formatCpuFromNano(raw string) string {
 	return fmt.Sprintf("%dm", milli)
 }
 
+// parseCpuNanoToMilli converts K8s metrics CPU (nanocores "100354992n") to millicores (int) // Logan.Li
+func parseCpuNanoToMilli(raw string) int {
+	if raw == "" { return 0 }
+	val := strings.TrimSuffix(raw, "n")
+	var nano int64
+	fmt.Sscanf(val, "%d", &nano)
+	milli := nano / 1000000
+	if milli < 1 { milli = 1 }
+	return int(milli)
+}
+
 // formatMemFromKi converts K8s metrics memory (Ki "2154292Ki") to Mi "2105Mi"
 func formatMemFromKi(raw string) string {
 	if raw == "" { return "" }
@@ -1939,6 +1982,15 @@ func formatMemFromKi(raw string) string {
 	return fmt.Sprintf("%dMi", mi)
 }
 
+// parseMemKiToMi converts K8s metrics memory (Ki "2154292Ki") to Mi (int) // Logan.Li
+func parseMemKiToMi(raw string) int {
+	if raw == "" { return 0 }
+	val := strings.TrimSuffix(raw, "Ki")
+	var ki int64
+	fmt.Sscanf(val, "%d", &ki)
+	return int(ki / 1024)
+}
+
 
 // GetResourceYAMLNS returns the YAML of a K8s resource
 func (h *KubernetesHandler) GetResourceYAMLNS(c *gin.Context) {