Emby orders (and this app already asked it to) by SortName, which
strips leading articles - an item like The Bunker sorts among the Bs
there, but the index was bucketing by the raw display name, throwing a
spurious T heading into the middle of that run. getLibraryItems/
getArtists now also fetch SortName, ItemDto carries it through, and the
index buckets by that instead - the same key Emby actually used to
order the array, not a guess that usually matches it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>