fix: direct K8s scaling, replicas from K8s API, button labels, modify fetch

- Add ScaleClient using K8s API (like kubectl scale deploy --replicas=N)
  - ScaleDeployment: patch Deployment.Spec.Replicas directly
  - GetDeploymentReplicas: query actual K8s deployment replicas
  - Search by labels then fallback to deployment name match
- Wire ScaleClient to InstanceService via SetScaleClient in main.go
- ModifyModal: fetch full instance detail on open (list excludes values)
- InstanceCard: add text labels to action buttons (Entries/Diag/Modify/Delete)
  - Text visible on sm+ screens, icon-only on xs

backend/internal/domain/service/instance_service.go

@@ -17,6 +17,12 @@ import (
 	"k8s.io/apimachinery/pkg/api/resource"
 )
 
+// ScaleClient defines the interface for K8s-native workload scaling
+type ScaleClient interface {
+	GetDeploymentReplicas(ctx context.Context, cluster *entity.Cluster, namespace, releaseName string) (int32, error)
+	ScaleDeployment(ctx context.Context, cluster *entity.Cluster, namespace, releaseName string, replicas int32) error
+}
+
 // InstanceService Helm 实例管理领域服务
 type InstanceService struct {
 	instanceRepo  repository.InstanceRepository
@@ -29,6 +35,7 @@ type InstanceService struct {
 	diagClient    repository.InstanceDiagnosticsClient
 	workspaceRepo repository.WorkspaceRepository
 	tenantClient  repository.TenantKubeClient
+	scaleClient   ScaleClient
 }
 
 // NewInstanceService 创建实例服务
@@ -60,6 +67,10 @@ func (s *InstanceService) SetDiagnosticsClient(client repository.InstanceDiagnos
 	s.diagClient = client
 }
 
+func (s *InstanceService) SetScaleClient(client ScaleClient) {
+	s.scaleClient = client
+}
+
 func (s *InstanceService) SetTenantProvisioning(workspaceRepo repository.WorkspaceRepository, tenantClient repository.TenantKubeClient) {
 	s.workspaceRepo = workspaceRepo
 	s.tenantClient = tenantClient
@@ -436,26 +447,44 @@ func (s *InstanceService) ScaleInstance(ctx context.Context, clusterID, instance
 		return nil, entity.ErrClusterNotFound
 	}
 
-	// Get existing Helm values and patch replicaCount
-	vals, err := s.helmClient.GetValues(ctx, cluster, instance.Name, instance.Namespace)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get current values: %w", err)
-	}
-	if vals == nil {
-		vals = make(map[string]interface{})
-	}
-	vals["replicaCount"] = replicas
-
-	instance.SetValues(vals)
-	instance.BeginOperation(entity.OperationUpgrade, fmt.Sprintf("Scaling to %d replicas", replicas))
-	if err := s.instanceRepo.Update(ctx, instance); err != nil {
-		return nil, err
+	// Scale via K8s API directly (like kubectl scale deploy --replicas=N)
+	if s.scaleClient != nil {
+		if err := s.scaleClient.ScaleDeployment(ctx, cluster, instance.Namespace, instance.Name, int32(replicas)); err != nil {
+			return nil, fmt.Errorf("failed to scale deployment: %w", err)
+		}
+	} else {
+		// Fallback: Helm upgrade with replicaCount
+		vals, err := s.helmClient.GetValues(ctx, cluster, instance.Name, instance.Namespace)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get current values: %w", err)
+		}
+		if vals == nil {
+			vals = make(map[string]interface{})
+		}
+		vals["replicaCount"] = replicas
+		instance.SetValues(vals)
+		instance.BeginOperation(entity.OperationUpgrade, fmt.Sprintf("Scaling to %d replicas", replicas))
+		if err := s.instanceRepo.Update(ctx, instance); err != nil {
+			return nil, err
+		}
+		go s.executeAndSyncUpgrade(context.Background(), instance.ID, cluster, nil, instance)
 	}
 
-	go s.executeAndSyncUpgrade(context.Background(), instance.ID, cluster, nil, instance)
 	return instance, nil
 }
 
+// GetRunningReplicas returns the actual K8s deployment replicas count.
+func (s *InstanceService) GetRunningReplicas(ctx context.Context, cluster *entity.Cluster, instance *entity.Instance) int {
+	if s.scaleClient == nil {
+		return 0
+	}
+	r, err := s.scaleClient.GetDeploymentReplicas(ctx, cluster, instance.Namespace, instance.Name)
+	if err != nil {
+		return 0
+	}
+	return int(r)
+}
+
 // GetInstanceValuesDiff 获取实例当前 values 与 chart 默认 values 的差异
 func (s *InstanceService) GetInstanceValuesDiff(ctx context.Context, clusterID, instanceID string) (*dto.InstanceValuesDiffResponse, error) {
 	principal, err := authz.RequirePrincipal(ctx)