fix: real K8s replicas in list API, full Helm values in modify YAML editor

- Add Replicas field to entity.Instance
- Add EnrichReplicas to InstanceService (batch K8s deployment query)
- convertInstanceResponse uses instance.Replicas instead of hardcoded 0
- ModifyModal: load full Helm values from values-diff API (Current deployed)
- Remove stale loadValuesDiff, use single useEffect for all data loading
- Fix YAML lineWidth:0 for no line wrapping

backend/internal/domain/entity/instance.go

@@ -53,6 +53,7 @@ type Instance struct {
 	Revision      int // Helm Release Revision
 	CreatedAt     time.Time
 	UpdatedAt     time.Time
+	Replicas      int // Running K8s replicas (enriched, not persisted)
 }
 
 // NewInstance 创建新实例

backend/internal/domain/service/instance_service.go

@@ -473,6 +473,24 @@ func (s *InstanceService) ScaleInstance(ctx context.Context, clusterID, instance
 	return instance, nil
 }
 
+// EnrichReplicas 批量获取实例的 K8s 实际副本数并设置到 entity 上
+func (s *InstanceService) EnrichReplicas(ctx context.Context, clusterID string, instances []*entity.Instance) []*entity.Instance {
+	if s.scaleClient == nil || len(instances) == 0 {
+		return instances
+	}
+	cluster, err := s.clusterRepo.GetByID(ctx, clusterID)
+	if err != nil {
+		return instances
+	}
+	for _, inst := range instances {
+		r, err := s.scaleClient.GetDeploymentReplicas(ctx, cluster, inst.Namespace, inst.Name)
+		if err == nil {
+			inst.Replicas = int(r)
+		}
+	}
+	return instances
+}
+
 // 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 {