[FEATURE] Turkish (tr-TR) UI localization for Claude Code

Preflight Checklist

• [ ] 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

Claude Code can already respond in Turkish via the language setting, but the interface itself stays English-only: permission prompts, /config and /help output, the slash-command list and descriptions, settings descriptions, and error messages.

This creates a mixed-language experience for Turkish-speaking developers. The conversation is in Turkish, while every prompt that asks for a decision (allow / deny, settings choices, error explanations) is in English. For users with limited English, these are exactly the places where a misunderstanding matters most.

This is a follow-up to #69348, which was auto-closed for inactivity without a maintainer response. It is related to the general request in #31413, where Turkish has also been requested by another user.

Proposed Solution

• Add a Turkish (tr-TR) locale for the Claude Code UI: menus, permission prompts, settings descriptions, slash-command descriptions, tooltips and error messages.
• Keep UI language separate from response language (for example a uiLanguage setting, as proposed in #31413), so users can combine them freely.
• If official translations for every language are not feasible, allow community-maintained locale files or localization plugins, similar to VS Code language packs.

I am a native Turkish speaker and I am willing to help translate and review the Turkish strings.

Alternative Solutions

Setting language to Turkish only changes Claude's responses, not the UI. Translating screenshots with external tools works, but interrupts the workflow on every prompt.

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

1. I set language to Turkish and work with Claude Code in Turkish.
2. Claude asks for permission to run a command. The prompt and its options are in English.
3. I open /config to change a setting. All option names and descriptions are in English.
4. With a Turkish locale, the whole flow would be in one language and I could make these decisions without translating first.

Additional Context

VS Code Turkish Language Pack, as an example of community-supported localization: https://marketplace.visualstudio.com/items?itemName=MS-CEINTL.vscode-language-pack-tr