Estimate: 45m · Type: design
Design the delete-work-item UX (the design gate for the UI subtask). Update design/work-items/ (three-file asset). Cover: the delete entry points (detail view ⋯ menu; list/board row context action — admin/permitted only), and the confirm dialog — warns it is permanent / can't be undone and names the cascade ("This deletes and its N descendants"), distinct from Archive (offered as the reversible alternative). States: no-children vs N-children, in-flight, error. Reuse the 5.3.6 delete-with-count confirm grammar.
design-notes.md + *.mock.html + .png updated/committed; copy index incl. the cascade + irreversibility warning and the archive-vs-delete distinction.components/ui/* + --el-*/shape tokens; AA-safe; full-page Playwright render.design/work-items/; existing confirm/dialog primitives; 5.3.6 pattern