[BUG] Claude Code npm package immediately enters interactive mode with OAuth expired error - authentication commands don't trigger OAuth flow

Environment

• Platform: Anthropic API
• Claude CLI version: 1.0.39 (Claude Code)
• Installation method: npm install -g @anthropic-ai/claude-code
• Operating System: macOS
• Terminal: Terminal.app and Cursor integrated terminal
• Node version: v22.17.0 (also tested with v23.11.0)

Bug Description
Claude Code immediately enters interactive mode when running claude command, and all authentication-related commands fail with OAuth expired error without ever triggering the browser OAuth flow.

Steps to Reproduce

1. Install Claude Code: npm install -g @anthropic-ai/claude-code
2. Run claude
3. Immediately drops into interactive mode with welcome message
4. Try any auth command: login, auth login, authenticate, auth
5. All return: API Error: 401 {"type":"error","error":{"type":"authentication_error","message":"OAuth token has expired. Please obtain a new token or refresh your existing token."}}

Expected Behavior
Running claude login should open browser for OAuth authentication

Actual Behavior
Never reaches OAuth flow, immediately shows expired token error in interactive mode

Troubleshooting Attempted

• Complete uninstall and cleanup of all config directories
• Tested with Node v22 and v23
• Removed macOS Keychain entries
• Fresh install multiple times