FE-1856: Restore React Compiler for the Live voice control and session indicator

[kostandinang]

🌟 What is the purpose of this PR?

Let React Compiler optimize LiveConversationControl and VoiceSessionIndicator again. Each contained a construct the compiler doesn't support, so it skipped the whole component without failing the build. LiveConversationControl compiled until #9829 and #9836. VoiceSessionIndicator hadn't compiled since #9467.

🔗 Related links

• FE-1856 (internal)
• Slack thread on using React Compiler instead of manual memoization (internal)
• #9899 fixes the same kind of skip in PinnedVoiceInterviewControl.

🚫 Blocked by

Nothing.

🔍 What does this change?

• LiveConversationControl:
  • The microphone check no longer uses finally, which the compiler doesn't support. Its catch handles every error, so resetting the checking state after the try behaves the same.
  • The Live bridge's mediation object moves into a createLiveMediation helper outside the component, because the compiler can't compile its history getter. The getter still reads the current conversation's history each time.
• VoiceSessionIndicator: colorRef.current ??= targetColor becomes an if, because the compiler doesn't support logical assignment operators.

Both components now compile with no compiler diagnostics.

Pre-Merge Checklist 🚀

🚢 Has this modified a publishable library?

This PR:

• does not modify any publishable blocks or libraries, or modifications do not need publishing

The @hashintel/petrinaut change doesn't change behaviour, so it has no changeset.

📜 Does this require a change to the docs?

The changes in this PR:

• are internal and do not require a docs change

🕸️ Does this require a change to the Turbo Graph?

The changes in this PR:

• do not affect the execution graph

⚠️ Known issues

• LiveConversationControl keeps its five useCallbacks. Each is a useEffect or useLayoutEffect dependency, and the react/exhaustive-deps lint rule fails on a plain function in a dependency list even when the compiler keeps it stable.
• Now that the compiler can analyze LiveConversationControl, react-hooks-js/set-state-in-effect warns about the setStartAwaitingStop(false) call in its voice-selection layout effect. It's a warning, not an error, and the code is unchanged.

🐾 Next steps

• LocalStorageDemoApp already compiles, so its manual useMemo and useCallback calls can go once #9894, which rewrites much of that file, lands. Some will stay for the same exhaustive-deps reason.

🛡 What tests cover this?

• No new tests: neither component's behaviour changes.
• Existing: the petrinaut-website voice-interview suite (540 tests) and Petrinaut's editor component tests (24) pass.

❓ How to test this?

1. Check out the branch and run the petrinaut-website dev server.
2. Confirm that Vite no longer prints React Compiler warnings for live-conversation-control.tsx or voice-session-indicator.tsx.
3. Open the AI assistant with GPT Live selected, run the microphone check, and start a Voice session. The check reports its result and the session indicator animates as before.

[vercel]

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Project	Deployment	Actions	Updated
hash	Ready	Preview	Oct 3, 2026 9:08pm UTC
petrinaut	Ready	Preview	Oct 3, 2026 9:08pm UTC
petrinaut-docs	Ready	Preview	Oct 3, 2026 9:08pm UTC

1 Skipped Deployment

Project	Deployment	Actions	Updated
hashdotdesign-tokens	Ignored	Preview	Oct 3, 2026 9:08pm UTC

[cursor]

PR Summary

Low Risk
Refactors only for compiler compatibility; voice mediation, microphone check, and canvas color initialization behave the same as before.

Overview
Re-enables React Compiler on LiveConversationControl and VoiceSessionIndicator by replacing patterns the compiler cannot analyze. Runtime behavior is unchanged.

In live conversation control, the Live bridge mediation config (dynamic history getter plus prepare / summarize / offered) is built via a createLiveMediation helper defined outside the component so the getter is no longer an inline object literal inside the component. The microphone-permission check clears checkingMicrophone after the try/catch instead of in a finally block.

In voice session indicator, initializing colorRef uses an explicit if (colorRef.current === null) instead of ??=.

^{Reviewed by Cursor Bugbot for commit 1115dc4. Bugbot is set up for automated code reviews on this repo. Configure here.}