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/domain/repository/helm_client.go

@@ -3,8 +3,21 @@ package repository
 import (
 	"context"
 	"github.com/ocdp/cluster-service/internal/domain/entity"
+	"k8s.io/apimachinery/pkg/api/resource"
 )
 
+type ResourceVector struct {
+	CPU         resource.Quantity
+	Memory      resource.Quantity
+	GPU         int64
+	GPUMemoryMB int64
+}
+
+type ResourceEstimate struct {
+	Requests ResourceVector
+	Limits   ResourceVector
+}
+
 // HelmClient Helm 客户端接口（Output Port）
 type HelmClient interface {
 	// Install 安装 Helm Chart
@@ -33,4 +46,7 @@ type HelmClient interface {
 
 	// GetChartDefaultValues 从 chart 包中读取默认 values
 	GetChartDefaultValues(chartPath string) (map[string]interface{}, error)
+
+	// EstimateInstanceResources renders an instance chart with final values and sums Pod template resources.
+	EstimateInstanceResources(ctx context.Context, cluster *entity.Cluster, instance *entity.Instance) (*ResourceEstimate, error)
 }

backend/internal/domain/repository/metrics_client.go

@@ -13,4 +13,7 @@ type MetricsClient interface {
 
 	// GetNodeMetrics 获取集群的节点指标
 	GetNodeMetrics(ctx context.Context, clusterID string) ([]*entity.NodeMetrics, error)
+
+	// GetPodResourceAllocations returns Pod requests/limits grouped by Pod.
+	GetPodResourceAllocations(ctx context.Context, clusterID string) ([]*entity.PodResourceAllocation, error)
 }

backend/internal/domain/repository/tenant_kube_client.go

@@ -11,5 +11,12 @@ import (
 type TenantKubeClient interface {
 	EnsureTenant(ctx context.Context, cluster *entity.Cluster, binding entity.TenantBinding) error
 	IssueKubeconfig(ctx context.Context, cluster *entity.Cluster, binding entity.TenantBinding, ttl time.Duration) (*entity.TenantKubeconfig, error)
+	GetResourceQuotaUsage(ctx context.Context, cluster *entity.Cluster, binding entity.TenantBinding) (*ResourceQuotaUsage, error)
 	SuspendTenant(ctx context.Context, cluster *entity.Cluster, binding entity.TenantBinding) error
+	DeleteTenant(ctx context.Context, cluster *entity.Cluster, binding entity.TenantBinding) error
+}
+
+type ResourceQuotaUsage struct {
+	Hard ResourceVector
+	Used ResourceVector
 }

backend/internal/domain/repository/workspace_repository.go

@@ -11,12 +11,14 @@ type WorkspaceRepository interface {
 	GetByID(ctx context.Context, id string) (*entity.Workspace, error)
 	GetByName(ctx context.Context, name string) (*entity.Workspace, error)
 	Update(ctx context.Context, workspace *entity.Workspace) error
+	Delete(ctx context.Context, id string) error
 	List(ctx context.Context) ([]*entity.Workspace, error)
 }
 
 type WorkspaceClusterBindingRepository interface {
 	Upsert(ctx context.Context, binding *entity.WorkspaceClusterBinding) error
 	Get(ctx context.Context, workspaceID, clusterID string) (*entity.WorkspaceClusterBinding, error)
+	ListByWorkspace(ctx context.Context, workspaceID string) ([]*entity.WorkspaceClusterBinding, error)
 	Delete(ctx context.Context, workspaceID, clusterID string) error
 }