Upgrade an app to tokens v2

Paths are relative to your Fresh app, such as apps/dashboard/. For the current theme chain, presets, and semantic overrides, see Theme your app.

Older apps keep working. [data-theme='dark'] and [data-theme='light'] still resolve NS One, and every earlier --ns-* property remains. To adopt the new attributes:

Move hand edits in assets/tokens.css into the override file where the alias layer can hold them. Applying a preset replaces the generated files.
Run netscript ui:apply --preset ns-one to generate theme-preset.json and fonts.json for the earlier look.
Update routes/_app.tsx and lib/theme.ts to match a new scaffold: stamp data-theme, data-density, and data-flavor on <html>, link the fonts, and make the preference script set data-scheme, keeping the ns-theme key. Update ThemeToggle and the light color-scheme selector the same way.
Run netscript ui:update to merge registry copies. It lists files you edited for a manual merge.
Switch presets with netscript ui:apply --preset studio-utility.

Component copies from 0.0.8 also need netscript ui:migrate variants. Preview it with --dry-run.