fix: restore Storybook styles, dark mode and brand fonts

[jaavid]

Closes #16

Root cause

Storybook loaded legacy global.css instead of the package stylesheet. Semantic tokens and component rules were therefore absent. The dark story only painted a dark wrapper, while text retained browser defaults. Font faces depended on local OS installations.

Fix

• load stable and experimental package styles in the preview
• configure light/dark themes through data-theme
• remove the preview-wide forced RTL wrapper
• define locale-aware typography tokens
• self-host Noto Sans, Noto Sans Arabic and Handjet through Fontsource
• align the Storybook canvas background and foreground with semantic tokens

Verification

CI, Storybook, deployed Cloudflare preview, computed fonts/colors, Persian RTL and English LTR will be checked before merge.

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[cloudflare-workers-and-pages]

Deploying design-system with    Cloudflare Pages

Latest commit:	82ec21e
Status:	✅  Deploy successful!
Preview URL:	https://80e6c50c.design-system-dby.pages.dev
Branch Preview URL:	https://fix-storybook-themes-and-fon.design-system-dby.pages.dev

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