feat: Add dual language selector for AI Transport guides

[GregHolmes]

Summary

Adds dual language selection for AI Transport guide pages, allowing users to independently choose Client (frontend) and Agent (backend) languages for code examples.

Changes

• Dual language selector UI: Two dropdowns ("Client" and "Agent") replace the single language selector on AI Transport guide pages
• URL param support: ?fe_lang=xxx&be_lang=yyy for bookmarking and sharing specific language combinations
• Navigation preservation: Language params persist when navigating between guide pages
• Code block prefixes: MDX files use fe_ and be_ prefixes (e.g., fe_javascript, be_python) to distinguish frontend vs backend code
• aiTransport languages: javascript, python, swift, java with SDK versions

Supported languages

• Client: JavaScript, Swift, Java
• Agent: JavaScript, Python, Java

Dependencies

• Requires @ably/[email protected] (or later) with fe_/be_ prefix support in CodeSnippet
• Also removes stale CookieMessage CSS import that was breaking builds with newer ably-ui versions

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on this repository. Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

• 🔍 Trigger a full review

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch AIT-108-Framework-language-feature-combos-investigate-and-design-navigation

Important

Action Needed: IP Allowlist Update

If your organization protects your Git platform with IP whitelisting, please add the new CodeRabbit IP address to your allowlist:

• ✨ 136.113.208.247/32 (new)
• 34.170.211.100/32
• 35.222.179.152/32

Reviews will stop working after February 8, 2026 if the new IP is not added to your allowlist.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}