A chart's series colours are named in docs/design/areas/chart.md, and .fg-s0….fg-s7 leave §5d #5499

For: the eight series colours the fleet graph draws its bars in (fg-s${i}, beside seriesDot()'s data-series) is one component, not a set of page-local classes waiting in docs/DESIGN.md §5d. It moves to its own area file, the way the design system now grows (scripts/design-lint.ts: an area file under docs/design/areas/ is vocabulary, and parallel pulls never edit the same lines).

Done:

• [ ] A new docs/design/areas/chart.md names the component, what it is for, the function that draws it (src/web/fleet-graph.ts) and each class in a code span: .fg-s0, .fg-s1, .fg-s2, .fg-s3, .fg-s4, .fg-s5, .fg-s6, .fg-s7. Follow docs/design/areas/README.md and the shape of the existing area files.
• [ ] Each of those classes' own lines leaves §5d in docs/DESIGN.md. Only those lines; §5d keeps one class per line, so other pulls never meet.
• [ ] No markup and no stylesheet rule changes. Every page that draws it looks the same as before.
• [ ] bun scripts/design-lint.ts passes, and so does the test that checks every defined class is documented.

Files: docs/design/areas/chart.md (new), docs/DESIGN.md (deleting lines in §5d only). Risk: none; documentation only. If design-lint asks for something else, follow what it names.