The reset layer now provides everything apps need for a dark-themed
shell: box model reset, font, background/color, font smoothing,
color-scheme: dark, and link reset. Apps no longer need to duplicate
these in their global CSS.

Consumers should:
- import '@duro-app/ui/dist/index.css' (includes reset)
- wrap app in <ThemeProvider>
- app global.css: empty or app-specific overrides only