[FEATURE] Conversation history titles should match the language used in the conversation

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When I use Claude Code entirely in Japanese (all my prompts and conversations are in Japanese), the conversation history titles in the left sidebar are always generated in English. This makes it difficult to find past conversations because the titles don't reflect the language I actually used.

I would expect the history titles to be generated in the same language as the conversation.

Proposed Solution

Automatically detect the language used in the conversation and generate history titles in that same language.

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_