Generate and apply full Digdir theme to KI Hub using Designsystemet

## Context

The Designsystemet team confirmed: all design tokens — colors, typography, spacing, border radius, margins — live inside the theme file you generate through Designsystemet's own tooling. There are no separate templates to investigate. The theme file **is** the foundation.

Reference:
- [Setup guide](https://designsystemet.no/no/fundamentals/code/setup)
- [Build your own theme](https://designsystemet.no/no/fundamentals/start-here/own-theme)

## Task

Use Designsystemet's CLI/tooling to generate the full Digdir theme file — including **all** available tokens:

- Colors (accent, brand, neutral, semantic)
- Typography (font family, sizes, weights, line heights)
- Spacing and margins
- Border radius
- Any other tokens Digdir's theme exposes

Apply the generated theme to KI Hub V2 so the full Digdir design language is available as a base. We do not need to use every token, but having the complete set means we can follow Digdir's design consistently without rebuilding things later.

## Acceptance Criteria

- [ ] Designsystemet CLI run against Digdir's theme config and full token set generated
- [ ] Theme applied to KI Hub V2 codebase
- [ ] Verified visually that KI Hub reflects Digdir's design (colors, fonts, radius at minimum)
- [ ] No hardcoded design values left where a theme token exists