Silences the dart-sass deprecation warnings that flooded every build:
- All @import of local partials (colors, mixins, and the CSS-emitting
partials) -> @use '...' as * (partials are pure defs, so 'as *' keeps the
global names and the ~25 call sites unchanged). Added explicit @use './colors'
to bootstrap-overrides.scss and cookies-eu.scss, which used -palette*
transitively (broke under @use's scoping).
- lighten(c, x%) -> color.adjust(c, $lightness: x%) and darken -> negative,
with @use 'sass:color' in the 6 affected files.
Compiles clean (byte-for-byte CSS behavior preserved).