Keep the server's order within sortIndex ties

Dart's List.sort is not stable, so on a page with more than 32 elements
tied rows could swap stacking between two loads of the same data. Sort
elements, lineups, and pages with a stable merge sort instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
47b32d088dDara Adedeji committed on 9/27/2026, 5:54:39 PMparente881a07
13 files changedLine totals unavailable