The diff file index now displays with a darker palette on dark mode,

fitting in with the rest of the unified banner and the review request

box.
The styling is based on the Ink data table styling, with uses a black

background, helping the graphs really pop.
While working on this, I noticed that the dividing lines between the

rows were blurred slightly in light mode. This turned out to be due to

the scrolling placement (via translateY) and box height, which was

using sub-pixel positioning. By rounding both of these value, we align

everything to the pixel grid, keeping presentation sharp.
Icon and text alignment has also been fixed. This stood out a lot more

on dark mode.

Tested in both light and dark modes, docked and undocked.