/web-setup loops to web onboarding despite gh CLI being authenticated

Description

Running /web-setup in Claude Code repeatedly reports:

GitHub CLI not authenticated. Run `gh auth login` and try again, or connect GitHub on the web: https://claude.ai/code/onboarding?step=alt-auth

This happens even though gh auth status and gh api user both confirm the CLI is authenticated and working:

$ gh auth status
github.com
  ✓ Logged in to github.com as LucaTNT (~/.config/gh/hosts.yml)
  ✓ Git operations for github.com configured to use ssh protocol.
  ✓ Token: *******************

Each retry of /web-setup opens a new claude.ai/code onboarding browser window instead of surfacing a more specific error.

Likely cause

My installed gh CLI is very outdated:

$ gh --version
gh version 1.2.0 (2020-10-27)

/web-setup's auth check likely depends on a gh output format or feature introduced after 1.2.0, causing it to misreport the auth state instead of detecting/reporting the outdated CLI version.

Suggested fix

• Detect an unsupported/outdated gh CLI version explicitly and surface that as the error (e.g. "gh CLI version X is too old, please upgrade") rather than falling through to a generic "not authenticated" message.
• Avoid silently repeating the same failed check / reopening the browser onboarding flow on repeated /web-setup runs without new information.

Environment

• Claude Code: 2.1.198
• macOS: 15.7.7 (24G720)
• gh CLI: 1.2.0 (installed via Homebrew, /usr/local/bin/gh -> ../Cellar/gh/1.2.0/bin/gh)