Feature Request: Japanese (日本語) UI localization support

Feature Request: Japanese (日本語) UI Localization

Summary

Please add Japanese language support to the Claude Code desktop app / Claude.ai interface UI.

Currently, all interface elements (menus, labels, buttons, filter options such as \"Status\", \"Project\", \"Environment\", \"Last activity\", \"Group by\", \"Sort by\", etc.) are displayed in English only. There is no option to switch the UI language to Japanese.

User Impact

Many Japanese users — including myself — use Claude Code daily but struggle with the English-only interface. The conversation content works perfectly in Japanese, but the UI chrome remains inaccessible without English proficiency.

Japan has a large and growing user base for AI tools. Japanese UI support would significantly lower the barrier to entry.

Request

• Add a language/locale setting to switch the UI language
• At minimum, support Japanese (ja-JP) as an additional language option
• Ideally, detect the OS/browser locale and apply it automatically

Submitted on behalf of: A Japanese user (katsuyasu-company project)

Priority from user perspective: High — daily friction for non-English-speaking users