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/oci_client.go

@@ -19,7 +19,10 @@ type OCIClient interface {
 	
 	// GetValuesSchema 获取 Helm Chart 的 values schema
 	GetValuesSchema(ctx context.Context, registry *entity.Registry, repository, reference string) (string, error)
-	
+
+	// GetValues 获取 Helm Chart 的 values.yaml
+	GetValues(ctx context.Context, registry *entity.Registry, repository, reference string) (string, error)
+
 	// PullArtifact 下载 artifact 到本地
 	PullArtifact(ctx context.Context, registry *entity.Registry, repository, reference, destPath string) error