Add light/dark mode support

[dvail]

No description provided.

[dvail]

This change is part of the following stack:

• Update from PF4 -> PF5 #1492
  • Update from PF5 -> PF6 #1493
    • Switch to Vite and react-query #1494
      • Add light/dark mode support #1495 ◀

_{Change managed by git-spice.}