One design system across the harness

When each surface (the web app, the desktop app, the docs, generated pages) keeps its own styles, they look like different products and every visual fix is made several times. So one design system is the single source for all of them.

The user, 2026-10-10: “we need the same set of design, elements, typo, etc shared, thorough the entire harness”.

• One design system (tokens, typography, elements, components) is the single source for the web UI, the desktop app, the docs and artifacts.
• No surface defines its own styles or copies components. New UI work consumes it; a difference between surfaces is a finding.

What is missing: the web cockpit has one token file (src/cockpit/tokens.css, described in DESIGN.md), but the docs site keeps its own stylesheets (scripts/floor/design-coverage.mjs checks the site against them, not against the shared tokens), and nothing yet shares one source across surfaces or refuses a surface’s own styles.