[muhannadalhariri]

Summary

Adds Modern Standard Arabic (ar-SA) as a selectable UI language, alongside the existing zh-CN, en-US and ru-RU locales. This is the UI counterpart to the docs translation in #375.

Arabic is the first right-to-left locale, so this PR also introduces RTL document-direction handling in the i18n layer.

What's included

• web/static/i18n/ar-SA.json — new Arabic locale, 4272 leaf strings, with full key and placeholder ({{…}}) parity against en-US. Register: فصحى / MSA.
• web/static/js/i18n.js
  • registers ar-SA and detects the ar* navigator language on first visit;
  • preloads en-US as a fallback bundle when Arabic is active;
  • sets document.documentElement.dir = "rtl" for Arabic (and "ltr" otherwise) via a new applyDirection() helper, called on init and on every language switch;
  • adds the ar-SA branch to the language-label updater and uiLocale().
  • fallback chain configured as ar-SA → en-US → zh-CN.
• web/static/i18n/{zh-CN,en-US,ru-RU}.json — add the lang.arSA ("العربية") label so the new option is named correctly in every existing locale.
• web/templates/{index,api-docs}.html — add the العربية option to the language dropdown.

Terminology

Technical and brand terms are kept verbatim (not transliterated): CyberStrikeAI, MCP, C2, WebShell, SQLite, Go, OpenAPI, Eino, RBAC, FOFA, i18next, the messaging-platform names (WeChat/iLink, WeCom, DingTalk, Lark, Telegram, Slack, Discord, QQ), all config keys, placeholders, code snippets, URLs, and {{…}} interpolation variables. A consistent glossary was applied across the file (e.g. Agent → الوكيل، Multi-Agent → تعدّد الوكلاء، Workflow → سير العمل، Dashboard → لوحة التحكّم، Knowledge Base → قاعدة المعرفة، HITL → التدخّل البشري).

Note on the c2 / webshell sections

The c2 and webshell string groups are intentionally omitted from ar-SA.json and fall back to English through the i18next fallback chain. An automated content safeguard in the translation tooling repeatedly blocked machine-translation of those two offensive-tooling sections, so rather than ship a partial or low-quality rendering they are left to render in English. The UI remains fully functional for Arabic users — those two panels simply display their English labels. They can be filled in later by a human translator in a follow-up.

Validation

• ar-SA.json is valid JSON (UTF-8, real Arabic characters).
• Recursive key parity vs. en-US (excluding the two deferred sections): 0 missing, 0 extra keys.
• Placeholder parity: 0 mismatches across all 4272 leaves.
• The 3 edited label files are valid JSON; i18n.js passes node --check.

🤖 Generated with Claude Code