When authenticating with Google Antigravity, the default model allowlist
now includes all commonly used models instead of just claude-opus-4-5-thinking:
- claude-opus-4-5-thinking
- claude-sonnet-4-5
- claude-sonnet-4-5-thinking
- gemini-3-flash
- gemini-3-pro
- gemini-2.5-flash
- gemini-2.5-pro
This ensures /models shows all available models after initial setup.
