migrate-design-system

# Skill: Migrate / Interop Design System Bridge to or from external design systems via a role-based crosswalk. ## Steps 1. Read `design-systems/interop-protocol.md` (Crosswalk Method, the three directions, headless-vs-styled guidance, verification). 2. Use the curated tables in `design-systems/crosswalk.md` for Material 3 / Apple HIG / Fluent 2 / Carbon / shadcn/ui / Radix. For others, derive a mapping with the Crosswalk Method (map by role/intent across 6 axes: color roles, type scale, spacing unit, radius, elevation, motion). 3. Choose the direction: - **FROM** external → our tokens (adopt their look): re-point `semantic.*`. - **TO** external stack (our components on their foundation): theme their primitives with our tokens. - **Migrate**: Audit → Map → Bridge (alias layer) → Verify, screen by screen. 4. **Verify** every mapped color pair for contrast (`scripts/contrast.py` / `a11y-audit`); confirm all 8 states + dark mode survive the mapping. ## Output A crosswalk table (our token → their token → value note), a bridge plan if migrating, and verified token overrides. Render via `design-code`.