[BUG] Auto mode temporarily unavailable on macOS - persists across restarts (v2.1.80)

Summary

Auto mode shows "temporarily unavailable" persistently. Cannot enter auto mode via Shift+Tab cycling or via defaultMode: "auto" in settings.json.

Environment

• Claude Code version: 2.1.80
• Install method: native (~/.local/share/claude/versions/2.1.80)
• OS: macOS Darwin 25.3.0
• Shell: zsh
• Model: claude-opus-4-6 (1M context)
• /doctor output: All checks pass (auto-updates enabled, latest version confirmed)

Behavior

1. Status bar shows auto mode temporarily unavailable
2. Shift+Tab cycles through Ask → Plan modes only — auto mode is skipped
3. Setting defaultMode: "auto" in ~/.claude/settings.json has no effect
4. Persists across multiple restarts and relaunches

Steps to Reproduce

1. Launch Claude Code v2.1.80 on macOS
2. Observe status bar: auto mode temporarily unavailable
3. Try Shift+Tab to cycle modes — auto mode is not reachable

What I've Tried

• Restarted Claude Code multiple times
• Ran /doctor — all checks pass
• Ran claude update — already on latest (2.1.80)
• Contacted Anthropic Support — received troubleshooting steps, none resolved the issue

Related Issues

This appears to be the same issue as #33587.

Expected Behavior

Auto mode should be available and selectable via Shift+Tab or defaultMode: "auto" setting.