Add unit test coverage for UserWorkflowComponent

[aglinxinyuan]

Task Summary

UserWorkflowComponent (frontend, dashboard/component/user/user-workflow/) is ~33% line-covered. Extend its spec to cover: deleteWorkflow, onClickDuplicateSelectedWorkflows (no-pid/with-pid/missing-wid/error), handleConfirmDeleteSelectedWorkflows, onClickOpenDownloadZip (+ error branch), local-file import (onClickUploadExistingWorkflowFromLocal: valid JSON / non-JSON / empty-name), zip import (handleZipUploads with a real in-test JSZip), nameWorkflow dedup, selection toggling/select-all/clear, setViewType persistence, tooltip updates, and the add/remove-workflow modal nzOnOk callbacks.

Task Type

• Refactor / Cleanup
• DevOps / Deployment / CI
• Testing / QA
• Documentation
• Performance
• Other