fix: send button not switching from voice button during IME composition

[FuanSol]

Description

Fixes #40146

The hasComposerPayload variable only checked the draft state, but during IME composition, handleEditorInput returns early and doesn't update draft. This caused the voice button to remain visible during CJK input.

Changes

1. Add composingVersion state - A dummy counter to force React re-renders when composition state changes
2. Check editor content directly - hasComposerPayload now also checks if the editor has content via composerPlainText(editorRef.current)
3. Trigger re-renders on composition events - Both onCompositionStart and onCompositionEnd now call setComposingVersion(v => v + 1) to force a re-render

Testing

• Tested with Microsoft Pinyin IME on Windows 10
• Voice button now switches to send button immediately when starting to type
• No flickering when committing Chinese characters
• English/number input still works as before

Code Changes

// Add state for forcing re-renders
const [composingVersion, setComposingVersion] = useState(0)

// Check editor content directly in hasComposerPayload
const hasComposerPayload = draft.trim().length > 0 || 
                          attachments.length > 0 || 
                          (editorRef.current && composerPlainText(editorRef.current).trim().length > 0)

// Trigger re-render on composition events
onCompositionStart={() => {
  composingRef.current = true
  setComposingVersion(v => v + 1)
}}
onCompositionEnd={() => {
  composingRef.current = false
  setComposingVersion(v => v + 1)
}}

[FuanSol]

Detailed Explanation of the Flickering Issue

The flickering occurs during the IME composition lifecycle:

Timeline of the Bug

1. User starts typing pinyin → compositionstart fires → composingRef.current = true
2. During composition → handleEditorInput returns early (skips updating draft)
3. User commits Chinese character (presses space) → compositionend fires → composingRef.current = false
4. At this exact moment:
   • draft is still empty (wasn't updated during composition)
   • composingRef.current is now false
   • hasComposerPayload = draft.trim().length > 0 || attachments.length > 0 evaluates to false
   • Button switches back to voice button ← This is the flicker!
5. Immediately after: input event fires → handleEditorInput updates draft
6. Button switches back to send button

Visual Representation

Time:     |---composition---|---commit---|---after---|
Button:   [SEND]            [VOICE]      [SEND]
                      ↑
              Flicker happens here

Why the Fix Works

By checking editorRef.current && composerPlainText(editorRef.current).trim().length > 0 directly, we read the editor's actual content instead of relying on the draft state. This ensures the button stays as "send" throughout the entire composition lifecycle, eliminating the flicker.

[FuanSol]

Sorry, after fixing this issue, another problem was discovered: when entering non-English characters, they cannot be sent directly. You must add a number or an English character after them for the input to be sent. I was worried that this might be caused by the change I made, so I closed the PR. However, after trying, I can't fix it in a short time. So, after some thought, I decided to raise the issue and reopen the PR.

[teknium1]

Thanks for the careful IME lifecycle analysis. This is now implemented on current main.

• apps/desktop/src/app/chat/composer/index.tsx:727-738 clears the composition flag and synchronously flushes the live editor text into composer state on compositionend, covering both the send-button visibility problem and the follow-up direct-submission problem described in the discussion.
• apps/desktop/src/app/chat/composer/ime-composition-dom-repro.test.tsx:61-106 covers committed Chinese, Japanese, and Korean text when no trailing input event is emitted.
• The implementation shipped in 8e629b9f386d12b726bccb32e9d7b48402ea73ea (fix(desktop): flush committed IME text on compositionend so the send button appears) and is contained in release tag v2026.6.19.

Automated hermes-sweeper review.