[BUG] /usage shows "only available for subscription plans" despite active Pro subscription

Description

The /usage command displays "only available for subscription plans" despite having an active Pro subscription (billingType: "stripe_subscription" in ~/.claude.json).

Environment

• Claude Code version: 2.1.81
• OS: macOS (Darwin 25.3.0)
• Shell: zsh
• Subscription: Pro (active, confirmed via billingType: "stripe_subscription" in config)

Steps to reproduce

1. Log in with an active Pro subscription (claude login)
2. Start a session (claude)
3. Run /usage
4. Error: "only available for subscription plans"

Root cause

hasAvailableSubscription in ~/.claude.json is set to false by the CLI on every session start, even though the OAuth account clearly has an active subscription. Manually setting it to true gets overwritten on next launch.

Additionally, oauthAccount.hasExtraUsageEnabled is also set to false.

What I've tried

• Logging out and back in (claude logout / claude login) — no effect
• Manually editing ~/.claude.json to set hasAvailableSubscription: true — works temporarily but gets reset on next session start
• Setting both hasAvailableSubscription and oauthAccount.hasExtraUsageEnabled to true — also gets reset

Expected behavior

/usage should correctly recognize the active subscription and display usage statistics.

Related issues

• #16646 — same error, closed without permanent fix
• #19879 — hasAvailableSubscription incorrectly set to false, closed as "not planned"
• #11915 — same /usage error with active subscription