Tag text was black in light themes and correctly tinted in dark. Both came from
liftMax(), which pushes lightness to an extreme, and the two extremes are not
symmetric: lightening past the sRGB gamut clips to a still-tinted color, so dark
kept its hue by accident, while darkening to zero lightness collapses every hue
to black.
Stopping short of the extreme keeps the hue in both appearances with no branch
on appearance, and still clears 6:1 against the tag's own surface across every
accent. Dark shifts from washed out toward the accent, so a purple tag now reads
purple rather than near-white pink.