ui gains a popup layer anchored to boxes (menus, filterable lists,
colour grids and a command palette) that fades in over everything and
closes on Escape or an outside press, and a virtualized list whose rows
ease to new places, fade in and out, and stay anchored on the selection
while items come and go. Combo lists open with their filter over the
combo itself.

Page tabs that aren't open float as pills beside the page, section tabs
keep their top edge as they rise, and rounded rectangles keep their
antialiased outer edge.

Assisted-by: claude-opus-5.5
Assisted-by: claude-opus-5