/usage command fails for Claude Max accounts

Description

The /usage command returns "usage is only available for subscription plans" even when authenticated with a Claude Max subscription account.

Steps to Reproduce

1. Log in to Claude Code with a Claude Max subscription account
2. Verify login via /status - shows "Login method: Claude Max Account"
3. Run /usage
4. Observe error: "usage is only available for subscription plans"

Expected Behavior

/usage should display plan usage limits and rate limit status for Claude Max accounts.

Actual Behavior

Returns error message suggesting the user doesn't have a subscription plan, despite being logged in with Claude Max.

Additional Context

• The web UI (claude.ai) also has issues displaying usage details for this account - only shows "extra usage" toggle instead of actual usage breakdown
• Account is at ~84% of weekly limit (confirmed via separate status check), so this isn't a "limit reached" display issue
• The /cost command works fine
• CLI otherwise functions normally

Environment

• Claude Code version: 2.1.1
• Login method: Claude Max Account
• Platform: Linux (devcontainer)