Theme Worlds

Re-map @theme tokens for a subtree — a per-case-study accent, a per-route palette, a per-scroll-act mode shift — using native CSS @scope and data-world/data-mode attribute scoping instead of a React ThemeProvider, keeping every value in tokens and every world AA-verified in both light and dark. Invoke opt-in when BRIEF.md flags a multi-brand, multi-tenant, or per-case-study need (agency portfolios, per-section palette shifts, a time-boxed campaign world), whenever award-canon's Scroll-as-Journey per-room data-mode or Content-Derived Color needs a scoped palette, or when the user says "per-case-study colors", "multi-brand theming", "a different accent per section/route", "…