fix(react-ui): stop voice-typing echo and duplication in composers

[shogun444]

What

Fixes an issue where using Windows Voice Typing (Win+H) and pressing Enter or Send mid-dictation causes text to duplicate in the draft (e.g., "welcome to Welcome to my house"), reappear after submission, or swallow subsequent speech.

This change introduces a shared composition hook that cleanly commits a single copy on the first Enter, drops trailing microphone noise, allows clean subsequent dictation to append without duplication, and ensures the draft remains cleared after sending.

Closes #1227

Refs #1045, #1068, #1228

Changes

• Unified composition handling: Consolidated dictation tracking across Composer and DesktopWelcomeComposer into useComposerComposition.
• Single-copy commit on fast Enter: The first Enter cleanly commits one snapshot to the draft and arms a 1500ms stopped window to swallow trailing speech remnants from the OS mic.
• Append without duplication: Once the 1500ms window expires, a subsequent Win+H session cleanly appends new text after the committed draft without repeating previous words.
• Submit-epoch guard: Increments an epoch counter upon submit to swallow late OS compositionend/onChange echoes, keeping the draft clean across rounds.
• Missing compositionend fallback: Automatically flushes pending commits if the OS fails to emit a terminal composition event.
• Preserved invariants: Preserved standard CJK IME conversion (keyCode === 229 / isComposing), Shift+Enter newlines, normal Send button click flow, and streaming cancellation.

Test Plan

• Not applicable (explain why)
• Verified locally

Environment

• OS: Windows 11 (25H2)
• Browsers: Google Chrome 153.0.8010.52, Microsoft Edge 154.0.4258.37

Validation Steps

1. Mid-dictation commit: Dictated phrases via Win+H and pressed Enter mid-speech $\rightarrow$ exactly one clean copy committed to the draft; trailing mic speech was ignored.
2. Send flow: Pressed a second Enter (or clicked Send) $\rightarrow$ message submitted cleanly; draft remained completely empty with no post-send echo.
3. Re-dictation: Dictated phrase $\rightarrow$ pressed Enter $\rightarrow$ pressed Win+H and dictated again $\rightarrow$ new speech appended directly after the committed text with no duplication.
4. Surfaces tested: Verified identical behavior on both Composer (thread view) and DesktopWelcomeComposer.
5. Standard typing: Verified that normal typing, Shift+Enter newlines, and CJK IME conversions remain unaffected.

Automated Tests

• Ran pnpm vitest run src/components/AgentInterface/__tests__/composerKeyboard.test.ts (all 26 tests passed).
• Ran pnpm run typecheck (no new errors introduced).

Demo

[

Video.Project.56.1.mp4

](url)

Checklist

• I linked a related issue, if applicable
• I updated docs/README when needed
• I considered backwards compatibility

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Project	Deployment	Actions	Updated
openui-docs	Ready	Preview	Sep 28, 2026 9:46am UTC