Knowledge Explorer Step 11: Detail Pages

Add routing. The search results stay at the root, and clicking a result opens a detail page at its own URL carrying the item id. Read that id with useParams and show the full record. Add a not-found route. Then do the part most projects skip: move focus to the heading on every route change and update the document title. Test it by tabbing to a result, pressing Enter, and confirming that focus lands somewhere sensible rather than at the top of the document or nowhere at all.