Rebuild /profile layout as zibll-style user-center flex (sidebar 320px
first, content flexes). Drop content-layout float shell classes so the
stats/assets nav stays left of the credits panel on desktop and drawer
on tablet/mobile.
Drop bare .sidebar from the profile aside so site-layout float/hide no
longer stacks stats/assets under content; harden page-owned grid + drawer
selectors on uc-sidebar/page-owned only.