[Bug] Web UI chat input: Chinese IME composition is frequently interrupted — text jumps and commits wrong characters when typing fast

[jingjing2026-bit]

Summary

When typing Chinese in the chat input box of the web UI (dsh web), the IME composition is frequently interrupted: while typing fast, previously entered pinyin letters get committed as wrong characters, the text in the input "jumps", and occasionally the input box re-fills with an older message that cannot be deleted. A page refresh temporarily restores normal behavior.

Environment

• OS: Windows 11 (Simplified Chinese), zh-CN
• Browser: Microsoft Edge / Chrome (recent versions)
• dsh version: 0.1.1-rc.2
• Web frontend: @deepseek-ai/dsh-web-frontend 0.1.1-rc.2
• Input method: Microsoft Pinyin (or third-party Chinese IME)

Steps to reproduce

1. Open the web UI (http://127.0.0.1:3080)
2. Switch to a Chinese IME and type quickly (e.g., type a full sentence with fast pinyin input)
3. Observe: the composition is interrupted mid-way — some characters commit as the pinyin letters' default candidates, or the text appears out of order
4. Occasionally: the input box re-displays the previously sent message and resists deletion until the page is refreshed

Expected behavior

• IME composition should be stable while typing; committing characters should match what was composed
• The input box should not be programmatically re-filled with stale content

Possible cause (from our investigation)

The composer appears to re-render or have its value reset during composition. Common triggers in web apps:

1. Controlled component value being restored from state while the IME composition is in progress (compositionstart/compositionend not guarded)
2. Re-render caused by streaming responses / websocket updates resetting the input
3. Input font-size below 16px triggers iOS auto-zoom (separate but related on mobile)

Suggested fix direction

• Guard the input value updates with composition events (compositionstart / compositionend / isComposing)
• Avoid resetting/restoring the input value from state during active composition
• Ensure the input has font-size >= 16px on mobile to prevent iOS focus zoom

Notes

This is a real usability issue for Chinese/Japanese/Korean (CJK) users who type with IMEs. Happy to provide more details or test a fix.