Feature request: i18n support for permission prompts and UI messages

Summary

Claude Code's permission prompts and UI messages are currently English-only. It would be great to support localization (i18n) so that non-English users can better understand what permissions are being requested.

Examples of messages that would benefit from localization

• "Claude requested permissions to edit /path/to/file which is a sensitive file."
• "Do you want to proceed?"
• "Yes, and always allow access to /path/ from this project"
• Other permission confirmation dialogs

Use case

Users who set their CLAUDE.md instructions to respond in a specific language (e.g., Japanese) still see English-only permission prompts. This creates a mixed-language experience that can be confusing, especially for users less comfortable with English.

Suggestion

• Add i18n support for CLI UI strings (permission prompts, status messages, menu options)
• Allow users to configure their preferred language in settings.json (e.g., "locale": "ja")
• Or auto-detect from system locale

Thank you!