docs: add live-data UX section + aesthetic acceptance checks
- Replace 7.6 (skeleton) with hairline + scanline-shimmer design that
matches the existing precision-instrument voice (Cabinet Grotesk + Geist
Mono, true-black + electric-blue, hairline chrome, radial light + grain)
- Add 7.7 Live-data UX patterns: skeleton variants, EmptyState primitive,
ErrorState primitive, Layout-level refetch indicator, Active filter chips,
newly-streamed row highlight, status color alignment, pagination footer
- Add 13.1 visual / aesthetic acceptance checks
- Voice decision: stay the course — additive only, no new accent / typeface /
layout primitive / light theme
Tyler
078de28cc4