Configurable workflow state colors

[mliebischer]

Problem

Two places currently hardcode the same workflow-state → color mapping independently:

• packages/contents/components/ReviewState.tsx (the state dot in the @@contents listing)
• packages/cmsui/components/History/HistoryView.tsx (statusDotClass, the "Action done" dot in the @@history view, added in [CMSUI] - History route #30 — deliberately mirroring the Contents mapping for visual consistency; marked with a TODO)

Both map published → --color-quanta-cobalt, private → --color-quanta-rose, versioning/green → --color-quanta-neon, and fall back to the neutral --color-quanta-pigeon for everything else.

This has two limitations:

1. Custom workflows: sites with their own workflows (other review states) only ever get the neutral fallback color. There is no way to register colors for additional states.
2. Theming: themes can re-color the dots only by overriding the Quanta token values globally. The mapping itself (which state gets which token) is not configurable.

Prior art

Volto solves this with a central, configurable mapping: config/Workflows.js → config.settings.workflowMapping, consumed by all components that render workflow states.

Proposal (to be discussed)

• A single source of truth for the mapping, registered through @plone/registry (e.g. config.settings), with the current four entries as the default.
• Values are design tokens (CSS custom properties), not hex values, so themes keep working.
• A small shared component/helper consumed by both @plone/contents and @plone/cmsui. Open question: which package may host it so that both can depend on it (@plone/layout? @plone/components would need to stay free of Plone-specific logic per the conventions).

Acceptance criteria

• Given a custom workflow state and a registered color for it, when the Contents listing or the History view renders that state, then the registered color is shown.
• Given no registered color for a state, then the neutral fallback is shown (current behavior).
• Contents and History render identical colors for identical states from the same source (no duplicated mapping).

References

• [CMSUI] - History route #30 (History route — where the duplication was flagged)
• packages/contents/components/ReviewState.tsx
• packages/cmsui/components/History/HistoryView.tsx (statusDotClass)
• Volto: src/config/Workflows.js, settings.workflowMapping