Sidebar nav clicks trigger a full page reload, which rebuilds the
sidebar from scratch and snaps .sidebar-nav back to scrollTop=0.
Persist scrollTop to sessionStorage (paliad.sidebar.scroll) on every
scroll and restore on initSidebar(). Re-apply once after
/api/user-views resolves so the async layout shift doesn't leave the
user a few rows off.
sessionStorage scopes the value to the tab: Cmd-click / right-click
"open in new tab" still produces a fresh tab that starts at the top.