feat: unified design system across agentsys and agnix sites

[avifenesh]

Context

Both agentsys and agnix have polished product sites but with different design systems:

• agentsys: custom HTML, dark theme, Linear/Vercel-inspired, tokens.css design system (Inter + JetBrains Mono, purple-to-cyan gradient, glass cards)
• agnix: Docusaurus, has its own color scheme and layout

The agent-sh.dev org hub uses the agentsys design tokens. All three sites should feel like they belong to the same org.

Scope

1. Extract the agentsys design tokens (tokens.css) into a shared design system
2. Create an agnix Docusaurus theme that uses the same tokens (dark background, accent colors, typography)
3. Align: nav style, footer layout, card patterns, code block styling, color palette
4. Keep each product's personality — just unify the foundation

Not in scope

• Merging sites into one (they stay separate repos with independent deploys)
• Changing content or information architecture

References

• agentsys tokens: site/assets/css/tokens.css
• agent-sh.dev: agent-sh/agent-sh.dev repo
• agnix site: agent-sh/agnix/website/
• Research: agent-knowledge/dev-tool-website-ux.md, agent-knowledge/multi-product-org-docs.md

[avifenesh]

[DONE] Task Completed Successfully

PRs:

• feat: import shared design tokens from design-system agentsys#268 (merged)
• feat: import shared design tokens from design-system #5 (merged)
• feat: import shared design tokens from design-system agnix#558 (merged)
• New repo: agent-sh/design-system (created)

Summary

• Created shared design-system repo with tokens.css (100+ CSS custom properties), base.css (reset + utilities), tokens-docusaurus.css (Infima bridge), and check-sync.sh
• All 3 sites now import from the shared source
• agnix switched from Outfit to Inter font, keeps teal accent and light/dark mode
• Removed render-blocking CSS @import for Google Fonts; each site loads via HTML link tags
• Review loop: 2 iterations, all critical/high/medium findings resolved