Add Knip and remove a bunch of unused code GitOrigin-RevId: 42ab99fc65973c883d2361e0027e7181767e714e
[web] Modify design-system-update split test GitOrigin-RevId: f28aeef5ba782006afd30fd2862d0ad129077f6c
[web] add split tests for tweaking user content domain access check GitOrigin-RevId: a5e6959098c10ea230634492b465c2b9dcdd909f