[BUG] /model picker does not offer Fable 5.1 to an account that is entitled to it (2.1.259, setup-token auth)

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?

The /model picker offers "Fable" = claude-fable-5[1m] only. Fable 5.1 is not listed, although the account is entitled to it:

• claude --model claude-fable-5-1 -p "Reply with exactly: OK" succeeds, as does the claude-fable-5-1[1m] variant.
• /model claude-fable-5-1[1m] is accepted and reports "Set model to Fable 5.1 and saved as your default for new sessions".
• The fable-5-1-launch startup announcement, which is gated on requiresModel: claude-fable-5-1 and says "Switch anytime with /model", has been shown five times on this install (announcementImpressions.fable-5-1-launch = 5 in ~/.claude.json).

So the model is usable; only the picker is wrong. ~/.claude.json has additionalModelOptionsCache with a single entry — {"value": "claude-fable-5[1m]", "label": "Fable", "description": "Fable 5 · Most capable for your hardest and longest-running tasks"} — and modelAccessCache: []. Other server caches on the install do refresh (cachedGrowthBookFeaturesAt was updated the same day), and restarting the CLI does not change the picker.

What Should Happen?

The /model picker lists Fable 5.1 for an account that is entitled to it, as the launch announcement promises.

Error Messages/Logs

# no error — the picker simply omits the entry

$ claude --version
2.1.259 (Claude Code)

$ claude --model claude-fable-5-1 -p "Reply with exactly: OK"
OK

$ claude --model 'claude-fable-5-1[1m]' -p "Reply with exactly: OK"
OK

Steps to Reproduce

1. Authenticate on a Claude Max account with a long-lived token: claude setup-token on a machine with a browser, then export it as CLAUDE_CODE_OAUTH_TOKEN on the target host (no browser /login there).
2. Start claude and run /model — the list shows Fable (5) but no Fable 5.1.
3. In a shell: claude --model claude-fable-5-1 -p "Reply with exactly: OK" — succeeds.
4. Back in the session: /model claude-fable-5-1[1m] — accepted, "Set model to Fable 5.1".
5. Inspect ~/.claude.json: additionalModelOptionsCache contains only the Fable 5 entry; announcementImpressions.fable-5-1-launch is non-zero.

Claude Model

Other

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.259 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

• Native install (~/.local/share/claude/versions/2.1.259), no ANTHROPIC_MODEL, no managed settings, no DISABLE_* env vars.
• Possible cause: additionalModelOptionsCache looks like a server-supplied per-account list that was never updated with the 5.1 entry, or its refresh is skipped under token-env auth. I could not tell which from the client side.
• I tried to send this through /feedback first. Under setup-token auth it fails with "Couldn't send feedback (server returned 403). The draft is still queued. Try again later." — consistent with long-lived tokens being inference-only, in which case "try again later" is misleading.