[AB Comparison] Change Tree Summary to show the same categories from detailed results

On the AB comparison page, the Tree Summary and detailed results use inconsistent status transition categories, which can be confusing for users.

We should align the Tree Summary categories with the ones used in the detailed results.

Start at the AB comparison page and compare the Tree Summary status transition categories with those shown in the detailed results. Update the Tree Summary so both views use the same categories, then verify that the displayed categories match.

Written by the indexing model from the issue text.