Cleaned scales from v4's measured usage: 11 control heights to 4, 19 radii to 6,
9px named as a real type step, one reduced-motion guard because every duration
is a token now.
Derived tokens are declared on [data-theme] as well as :root -- a custom
property's var()s are substituted where it is declared, so on :root alone a
scoped light subtree inherits the dark accent.
The catalogue reads the tokens out of the stylesheet instead of listing them, so
it cannot drift; anything it has no renderer for shows up as Ungrouped.
