## Summary The file tree browser currently uses a `div` container with `role="tree"` and individual `file-row` components with `role="treeitem"`. For better semantic HTML, we should refactor this to use native `ul` and `li` elements with proper ARIA attributes. ## Context This was identified during the review of !207844 where we replaced RecycleScroller with a standard scroller. The [W3C Tree View pattern](https://www.w3.org/WAI/ARIA/apg/patterns/treeview/examples/treeview-1b/) uses `ul` and `li` elements for the tree structure. ## Proposal Refactor the tree list structure to use: - Nested `ul` elements for hierarchy (directory/subdirectory/etc.) - `li` elements for each tree item - Maintain existing ARIA attributes (`role="tree"`, `role="treeitem"`, etc.) ## Benefits - More semantic HTML structure - Better accessibility for screen readers - Follows W3C best practices for tree view patterns ## Implementation Notes This will require a larger refactor as we'll need to handle nested `ul` elements for the directory hierarchy. The current flat list structure will need to be adapted to support proper nesting. ## Related - !207844 - Replace RecycleScroller with standard scroller - #541107 - Navigate repository with file tree browser - &17973 - [Post-Rollout] Navigate repo with a file tree