Session titles generated in English despite locale set to ko-KR

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code generates session titles (ai-title events in the JSONL transcript files) in English, even though the app locale is explicitly set to ko-KR in config.json. The Claude web interface correctly generates Korean titles under the same account and locale setting.

What Should Happen?

Session titles in the sidebar Recents list should be generated in Korean (or the user's locale language) when locale is set to ko-KR — matching the behavior of Claude web.

Error Messages/Logs

Steps to Reproduce

1. Set Claude app locale to ko-KR (already reflected in AppData/Roaming/Claude/config.json as "locale": "ko-KR")
2. Start a new Claude Code session and have a conversation in Korean
3. Open the left sidebar Recents panel
4. Observe: session title is auto-generated in English (ai-title event in ~/.claude/projects/.../session.jsonl)
5. Compare with Claude web: same account generates Korean titles

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.156 (claude-desktop, Windows)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Confirmed by directly inspecting ~/.claude/projects/ JSONL files. All ai-title events contain English strings despite locale: ko-KR in config.json. Claude web generates Korean titles correctly. This appears to be a locale propagation issue in Claude Code's internal title generation call.