[BUG] Account & Usage shows "Plan: Claude api" instead of Max plan after recent update

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?

After a recent platform update (around 2026-03-17), the "Account & Usage" dialog
shows "Plan: Claude api" even though the account has a Max plan and is authenticated
correctly via Claude.ai OAuth.

Auth method shown: Claude AI (correct)
Plan shown: Claude api (incorrect — should show Max)
ANTHROPIC_API_KEY: not set in environment

Steps to reproduce:

1. Open Claude Code
2. Click on account icon → "Account & Usage"
3. Plan shows "Claude api" instead of Max

I have done /logout and /login again — issue persists.
The usage percentages (Weekly 24%, Weekly Sonnet 39%) are being tracked,
so the plan seems active but the label is wrong.

What Should Happen?

The "Plan" field in "Account & Usage" should correctly display
the user's active plan (Max), not "Claude api", when the user
is authenticated via Claude.ai OAuth and no API key is configured.

Error Messages/Logs

Steps to Reproduce

1. Have a Max plan account authenticated via Claude.ai OAuth
2. Open Claude Code (VSCode extension or terminal)
3. Click on account icon → "Account & Usage"
4. Observe "Plan" field shows "Claude api" instead of Max
5. Run /logout then /login again using Claude.ai option
6. Check "Account & Usage" again — issue persists
7. Confirm ANTHROPIC_API_KEY is not set in environment (echo $ANTHROPIC_API_KEY returns empty)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.78

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_