[BUG] Subscription gets ignored when an API key env variable is set

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?

When I try to switch to my Pro subscription, Claude Code would look at my key and say i don't have any usage.

<img width="1026" height="788" alt="Image" src="https://github.com/user-attachments/assets/8f713a7c-4900-4f8f-9928-f1300884e03f" />

What Should Happen?

IT should tell me that I have an API key set, and that if want to use my Subscription i need to clear the env api key.

Error Messages/Logs

You don't have any usage left.

Steps to Reproduce

set an API key with a balance of 0, then try to set it to use subscription. and login.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.70

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

_No response_