/usage says 'only available for subscription plans' while /cost confirms active subscription

Bug Description

/cost and /usage contradict each other regarding subscription status:

• /cost reports: "You are currently using your subscription to power your Claude Code usage" — correctly recognizing the subscription.
• /usage reports: "/usage is only available for subscription plans." — implying no subscription is detected.

Steps to Reproduce

1. Run /cost — confirms subscription is active
2. Run /usage — claims the feature is only available for subscription plans

Expected Behavior

/usage should recognize the subscription and display usage information, consistent with /cost.

Actual Behavior

/usage fails to detect the subscription that /cost correctly identifies, and blocks access to usage data.

Screenshot

<img width="337" height="75" alt="Image" src="https://github.com/user-attachments/assets/3098dd13-ff35-452d-82db-3f4c440d5b66" />

<img width="686" height="292" alt="Image" src="https://github.com/user-attachments/assets/dd63eee9-dc3b-4fee-8603-b0b9496734a3" />

Environment

• Platform: macOS (Darwin 25.3.0)
• Claude Code: CLI
• Model: Claude Opus 4.6