docs: rebuild bilingual documentation

[RlxChap2]

Closes: #3

Summary

• Rebuild the documentation around a bilingual locales/ structure for English and Arabic.
• Document all 31 supported GET operations with generated OpenAPI contracts, endpoint pages, SDK guidance, and diagrams.
• Preserve legacy documentation URLs through redirects while keeping language navigation and RTL behavior consistent.
• Add source-aware generation, validation, link checking, and CI coverage for documentation changes.

Validation

• pnpm check
• pnpm build
• pnpm broken-links
• node scripts/check-source.mjs <Bonyan-API> <bonyan-sdk-js>