fix(desktop): IME composition prevents send button from switching to arrow

[chenyf1010]

Summary

Fix CJK IME composition causing the send button to stay as microphone icon instead of switching to the up-arrow after Chinese/Japanese/Korean input.

Root Cause

The onCompositionEnd handler only set composingRef.current = false without syncing the composer state with the final DOM content. As a result, draft stays empty, hasComposerPayload remains false, and the button stays as voice/microphone icon.

Fix

Added state sync logic in onCompositionEnd that reads the final committed text from the editor DOM and pushes it to aui.composer().setText(). The sync is wrapped in setTimeout(0) to avoid React 18 automatic batching swallowing the state update.

Test Plan

• Type Chinese characters using IME in Hermes Desktop -> verify send button switches to up-arrow immediately
• Type English text normally -> no regression
• Start a voice conversation -> no regression on microphone button

[teknium1]

Thanks for the IME-focused report and proposed fix. This is an automated hermes-sweeper review; the requested behavior is already implemented on current main.

• apps/desktop/src/app/chat/composer/index.tsx:727 clears the composition flag and synchronously calls flushEditorToDraft(event.currentTarget).
• apps/desktop/src/app/chat/composer/index.tsx:262 serializes the finalized editor DOM and updates both draftRef and the assistant-ui composer state that drives hasComposerPayload.
• The equivalent fix landed as 8e629b9f386d12b726bccb32e9d7b48402ea73ea (fix(desktop): flush committed IME text on compositionend so the send button appears) and is covered by apps/desktop/src/app/chat/composer/ime-composition-dom-repro.test.tsx:61.

Closing as implemented on main.