fix: scale replicas in response, K8s metrics client, quota precheck, auth tests

- Add GetMetrics method to MetricsClient interface and implement cluster metrics API
- Add QuotaPrecheck service for validating resource quotas before deployment
- Add auth DTO with role/permission models and auth handler tests
- Add instance diagnostics: mounted NFS volumes, labels, annotations in pod diagnostics
- Update workspace handler with GetWorkspace endpoint and shared-user list
- Fix monitoring handler to use correct service method name
- Add tail_lines fallback in instance handler for snake_case query params
- Update nginx config for SSE log streaming support (no buffering)
- Add comprehensive test coverage: auth_service_test, auth_handler_test,
  auth_dto_test, metrics_client_test, quota_precheck_test
- Update error messages for quota validation and instance operations
- ModifyModal: fix YAML lineWidth:0, modified keys summary, delta-only submit
- InstanceCard: correctly disable scale-minus when replicas <= 0
- SidebarLayout: add hover transition for sidebar items
- Update todo.md and lessons.md with latest fixes

backend/internal/adapter/output/helm/real/helm_client.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/ocdp/cluster-service/internal/domain/entity"
 	"github.com/ocdp/cluster-service/internal/domain/repository"
+	domainservice "github.com/ocdp/cluster-service/internal/domain/service"
 	"helm.sh/helm/v3/pkg/action"
 	"helm.sh/helm/v3/pkg/chart/loader"
 	"helm.sh/helm/v3/pkg/cli"
@@ -346,6 +347,41 @@ func (h *HelmClient) GetChartDefaultValues(chartPath string) (map[string]interfa
 	return vals, nil
 }
 
+func (h *HelmClient) EstimateInstanceResources(ctx context.Context, cluster *entity.Cluster, instance *entity.Instance) (*repository.ResourceEstimate, error) {
+	chartPath := fmt.Sprintf("/tmp/charts/%s-%s.tgz", instance.Chart, instance.Version)
+	chart, err := loader.Load(chartPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load chart: %w", err)
+	}
+	actionConfig := new(action.Configuration)
+	actionConfig.Log = func(format string, v ...interface{}) {}
+
+	install := action.NewInstall(actionConfig)
+	install.ReleaseName = instance.Name
+	if install.ReleaseName == "" {
+		install.ReleaseName = "quota-precheck"
+	}
+	install.Namespace = instance.Namespace
+	if install.Namespace == "" {
+		install.Namespace = "default"
+	}
+	install.DryRun = true
+	install.DryRunOption = "client"
+	install.ClientOnly = true
+	install.Replace = true
+	install.SkipSchemaValidation = true
+
+	values := instance.Values
+	if values == nil {
+		values = map[string]interface{}{}
+	}
+	release, err := install.RunWithContext(ctx, chart, values)
+	if err != nil {
+		return nil, fmt.Errorf("failed to render chart for quota estimate: %w", err)
+	}
+	return domainservice.EstimateRenderedManifestResources(release.Manifest)
+}
+
 // convertReleaseToInstance 转换 Helm Release 为 Instance
 func (h *HelmClient) convertReleaseToInstance(rel *release.Release) *entity.Instance {
 	return &entity.Instance{