feat(design-system): add type scale, spacing rhythm and font tokens
Apply the Phase 2 warm-premium base additively (no existing page changes):
- tailwind.config.ts: add fontSize roles (display, h1, h2, h3, title, body-lg,
body, small, caption, overline) with line-height/tracking/weight; add
fontFamily (sans/latin = Museo, arabic = Dubai); add section-sm/section-lg
spacing rhythm.
- globals.css: add Arabic-safe .eyebrow utility (uppercase + tracking on Latin,
neutralised for html[lang="ar"]).
Colors and fonts unchanged. Verified: tsc clean, eslint clean, tailwind build
generates the new utilities with correct values.