Fix: message element prerendering

[uni-kakurenbo]

概要

なぜこの PR を入れたいのか

動作確認の手順

UI 変更部分のスクリーンショット

before

after

PR を出す前の確認事項

• （機能の追加なら）追加することの合意がチームで取れている
  • 取れていない場合はチェックを外して PR にすれば OK
• 動作確認ができている
• 自分で一度コードを眺めて自分的に問題はなさそう

見てほしいところ・聞きたいことなど

[github-actions]

Preview (prod) → https://5034-prod.traq-preview.trapti.tech/
Preview (dev) → https://5034-dev.traq-preview.trapti.tech/

[codecov]

Codecov Report

❌ Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.62%. Comparing base (377987c) to head (5811eeb).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
src/lib/basic/timer.ts	25.00%	3 Missing ⚠️
src/lib/basic/arithmetic.ts	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5034      +/-   ##
==========================================
- Coverage   62.69%   62.62%   -0.07%     
==========================================
  Files         108      108              
  Lines        3091     3096       +5     
  Branches      629      629              
==========================================
+ Hits         1938     1939       +1     
- Misses       1043     1047       +4     
  Partials      110      110              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.