Rule that an interactive data chart is not a plate

Andrew Dunnrequested to merge
design/data-chart-convention into main

What does this MR do and why?

I want the diagram conventions to say what a data chart follows, because a sizing tool's d3 charts resize with their container and respond to sliders, and the plate rules assume a fixed viewBox they cannot have. A new Data charts section rules that an interactive or container-sized chart is not a plate and conforms when its colors, type, stroke and dash come from the design tokens. The fixed viewBox, 4px grid, radii, plate scaffold and retoken.py --check apply to static plates, and a static chart is still a plate.

The same tool's page classes collide with chrome/docs/index.css. The design standard now says such an app page links only chrome/docs/tokens.css and fonts/fonts.css, pinned to a tag, in place of the full docs chrome. I put it in the CDN section because that is where the reference says which bundle a page loads. A CHANGELOG Changed entry records both.

References

None.

Standards affected

design: prose in SKILL.md only. check.sh and the generated Verify block are unchanged.

Exemption implications

None.

Test plan

  • just guard, just validate, just check REPO=$PWD, just build and just agent pass.
  • The diff adds no em-dash and no spaced double hyphen.
  • Not tested: a chart built to the new rule. The section states the ruling and has no checker, because the plate checker does not run on markup a script draws.
  • design/v2.7.0/chrome/docs/tokens.css and design/v2.7.0/fonts/fonts.css both return 200 on the published site, and tokens.css has no @import.

An AI tool wrote this change and ran the checks above.

Merge request reports