[Bug] Unexpected non-ASCII characters in Claude Code output

Bug Description
Claude's anomalous use of design问题 is interesting: perhaps an example of reward-hacking by avoiding stating that there's an architectural issue with my project?

Environment Info

• Platform: linux
• Terminal: xterm-256color
• Version: 2.1.207
• Feedback ID: 289c95c7-69ad-4be2-bf4e-59df9a16ca98

<img width="341" height="44" alt="Image" src="https://github.com/user-attachments/assets/dc970303-99b0-4835-8fc7-9220c197f69c" />

Google translate gives the word as "problem", "issue", "matter", "trouble", "topic", "point", or "mishap". I practically never encounter anomalous tokens with Opus-4.8, so this was noteworthy