fix(capacity): 忽略未就绪的 Worker 节点

香港站点保留了已离线的旧 control-plane 节点标签，容量控制器仍尝试读取其 metrics，导致 404 并阻断 readiness。容量采集现在只纳入 Ready=True 的候选节点，实际 Worker Pod 所在的就绪节点继续参与容量计算。

验证：容量控制器聚焦测试与 API 全量 go test 均通过，并覆盖同站点 NotReady 旧节点与 Ready Worker 节点并存场景。

apps/api/internal/capacitycontroller/kubernetes.go

@@ -178,6 +178,20 @@ func (client *KubernetesClient) SiteState(ctx context.Context, site string) (Kub
 	if err := client.getJSON(ctx, nodePath, &nodes); err != nil {
 		return KubernetesSiteState{}, err
 	}
+	readyNodes := nodes.Items[:0]
+	for _, node := range nodes.Items {
+		ready := false
+		for _, condition := range node.Status.Conditions {
+			if condition.Type == "Ready" && condition.Status == "True" {
+				ready = true
+				break
+			}
+		}
+		if ready {
+			readyNodes = append(readyNodes, node)
+		}
+	}
+	nodes.Items = readyNodes
 	if len(nodes.Items) == 0 {
 		// A zero-replica Deployment with no eligible nodes represents an
 		// explicitly disabled site. It must remain visible to the planner, but it
@@ -186,7 +200,7 @@ func (client *KubernetesClient) SiteState(ctx context.Context, site string) (Kub
 		if state.CurrentReplicas == 0 {
 			return state, nil
 		}
-		return KubernetesSiteState{}, fmt.Errorf("site %s has no matching nodes", site)
+		return KubernetesSiteState{}, fmt.Errorf("site %s has no ready matching nodes", site)
 	}
 	var pods struct {
 		Items []struct {

apps/api/internal/capacitycontroller/kubernetes_test.go

@@ -31,15 +31,24 @@ func TestKubernetesClientReadsSiteAndMutatesOnlyWorkerScale(t *testing.T) {
 				http.Error(w, "unexpected Worker node selector", http.StatusBadRequest)
 				return
 			}
-			_, _ = w.Write([]byte(`{"items":[{"metadata":{"name":"easyai-hongkong"},"status":{
+			_, _ = w.Write([]byte(`{"items":[
+			{"metadata":{"name":"easyai-hongkong"},"status":{
 				"allocatable":{"memory":"8Gi","cpu":"4"},
-				"conditions":[{"type":"MemoryPressure","status":"False"}]
+				"conditions":[{"type":"Ready","status":"False"}]
+			}},
+			{"metadata":{"name":"easyai-hongkong-worker-2"},"status":{
+				"allocatable":{"memory":"8Gi","cpu":"4"},
+				"conditions":[{"type":"Ready","status":"True"},{"type":"MemoryPressure","status":"False"}]
 			}}]}`))
 		case request.Method == http.MethodGet && strings.Contains(request.URL.Path, "/api/v1/namespaces/easyai/pods"):
-			_, _ = w.Write([]byte(`{"items":[{"metadata":{"name":"worker-hongkong-1"},"spec":{"nodeName":"easyai-hongkong"}}]}`))
+			_, _ = w.Write([]byte(`{"items":[{"metadata":{"name":"worker-hongkong-1"},"spec":{"nodeName":"easyai-hongkong-worker-2"}}]}`))
+		case request.Method == http.MethodGet && strings.Contains(request.URL.Path, "/metrics.k8s.io/") &&
+			strings.HasSuffix(request.URL.Path, "/nodes/easyai-hongkong-worker-2"):
+			_, _ = w.Write([]byte(`{"usage":{"memory":"3Gi","cpu":"500m"}}`))
 		case request.Method == http.MethodGet && strings.Contains(request.URL.Path, "/metrics.k8s.io/") &&
 			strings.HasSuffix(request.URL.Path, "/nodes/easyai-hongkong"):
-			_, _ = w.Write([]byte(`{"usage":{"memory":"3Gi","cpu":"500m"}}`))
+			t.Error("NotReady node metrics must not be queried")
+			http.Error(w, "NotReady node", http.StatusInternalServerError)
 		case request.Method == http.MethodGet && strings.Contains(request.URL.Path, "/metrics.k8s.io/") &&
 			strings.HasSuffix(request.URL.Path, "/pods"):
 			_, _ = w.Write([]byte(`{"items":[{
@@ -69,7 +78,7 @@ func TestKubernetesClientReadsSiteAndMutatesOnlyWorkerScale(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if state.CurrentReplicas != 1 || state.NodeName != "easyai-hongkong" ||
+	if state.CurrentReplicas != 1 || state.NodeName != "easyai-hongkong-worker-2" ||
 		state.WorkerRequestMemoryBytes != 512<<20 || state.WorkerRequestMilliCPU != 250 ||
 		state.AllocatableMemoryBytes != 8<<30 || state.UsedMemoryBytes != 3<<30 ||
 		state.Nodes[0].WorkerUsedMemoryBytes != 384<<20 || state.Nodes[0].WorkerUsedMilliCPU != 125 {
@@ -148,7 +157,7 @@ func TestKubernetesClientRejectsActiveSiteWithoutWorkerNodes(t *testing.T) {
 		t.Fatal(err)
 	}
 	if _, err := client.SiteState(context.Background(), "ningbo"); err == nil ||
-		!strings.Contains(err.Error(), "site ningbo has no matching nodes") {
+		!strings.Contains(err.Error(), "site ningbo has no ready matching nodes") {
 		t.Fatalf("expected missing Worker node error, got %v", err)
 	}
 }