feat(frontend): add Helm chart browser, monitoring, chart-references and values templates pages

Add new frontend pages for the multi-tenant OCDP platform:

- Charts page (/charts): Browse Harbor OCI registries to list Helm chart repositories
  and versions, with deploy modal to launch charts on selected clusters
- Monitoring page (/monitoring): Display cluster metrics (CPU/Memory/GPU usage)
  and per-node details with resource utilization bars
- Chart References page (/chart-references): CRUD for chart metadata references
- Values Templates page (/templates): CRUD for Helm values templates with version
  history and rollback support
- Sidebar: Add Charts navigation, update Storage and Templates links
- api.ts: Add all API client functions (clusterApi, registryApi, instanceApi,
  monitoringApi, storageApi, chartReferenceApi, valuesTemplateApi,
  workspaceApi, userApi) with full TypeScript types

Note: deploy flow and values template rollback not yet end-to-end tested.

backend/internal/domain/repository/instance_repository.go

@@ -9,23 +9,26 @@ import (
 type InstanceRepository interface {
 	// Create 创建实例
 	Create(ctx context.Context, instance *entity.Instance) error
-	
+
 	// GetByID 根据 ID 获取实例
 	GetByID(ctx context.Context, id string) (*entity.Instance, error)
-	
+
 	// GetByClusterAndName 根据集群 ID 和名称获取实例
 	GetByClusterAndName(ctx context.Context, clusterID, name string) (*entity.Instance, error)
-	
+
 	// Update 更新实例
 	Update(ctx context.Context, instance *entity.Instance) error
-	
+
 	// Delete 删除实例
 	Delete(ctx context.Context, id string) error
-	
+
 	// ListByCluster 列出指定集群的所有实例
 	ListByCluster(ctx context.Context, clusterID string) ([]*entity.Instance, error)
-	
+
 	// List 列出所有实例
 	List(ctx context.Context) ([]*entity.Instance, error)
+
+	// GetByWorkspace 列出指定工作空间的所有实例（用于配额检查）
+	GetByWorkspace(ctx context.Context, workspaceID string) ([]*entity.Instance, error)
 }