Max plan: opus[1m] not available, Default shows Sonnet instead of Opus

Bug Description

On a confirmed Max 20x plan, opus[1m] is not available and the /model picker does not show any 1M context options. Additionally, the Default (recommended) model shows Sonnet 4.6 instead of Opus 4.6, which suggests Claude Code is not recognizing the Max plan entitlements.

Expected Behavior

• Default (recommended) should be Opus 4.6 (per docs: "Max and Team Premium: defaults to Opus 4.6")
• opus[1m] and sonnet[1m] should appear in the /model picker
• /model opus[1m] should work (1M context is included with Max subscription per docs)

Actual Behavior

• /model opus[1m] returns: "Opus 4.6 with 1M context is not available for your account"
• Default (recommended) = Sonnet 4.6 (Pro-tier behavior)
• No 1M options visible in /model picker at all
• Only 3 options shown: Default (Sonnet 4.6), Opus, Haiku

Environment

• Claude Code version: 2.1.90 (latest)
• Platform: macOS (Darwin 25.3.0)
• Auth: CLAUDE_CODE_OAUTH_TOKEN
• Plan: Max 20x ($200/month, confirmed in claude.ai settings)
• CLAUDE_CODE_DISABLE_1M_CONTEXT: not set

Steps to Reproduce

1. Have a Max 20x plan (confirmed at claude.ai/settings/billing)
2. Run claude (v2.1.90)
3. Run /model opus[1m] → error
4. Open /model picker → no 1M options shown
5. Check /status → Default = Sonnet 4.6

Attempted Fixes

• claude update — already on latest (2.1.90)
• /upgrade (re-authentication) — no change
• Verified CLAUDE_CODE_DISABLE_1M_CONTEXT is not set
• Restarted session — no change