Default model does not work

### Description of the bug:

- The default model `gemini-2.5-computer-use-preview-10-2025` does not work for the free gemini api key.
(not sure if it happens for paid api plan too).
- However, the model `gemini-3-flash-preview` works fine.

### Actual vs expected behavior:

## Actual:
When the computer use script is run with the defaults:
`python main.py --query="Go to Google and type 'Hello World' into the search bar"`
It gives errors even on the first try
```
google.genai.errors.ClientError: 429 RESOURCE_EXHAUSTED. {'error': {'code': 429, 'message': 'You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. ...
```

## Expected
The computer use script should work with the default model, even for the free gemini api key.
Probably the default model should be updated to `gemini-3-flash-preview`.
This model gives the correct output something like this:
```
Gemini Computer Use Reasoning ┃ Function Call(s) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ **My Google Search Protocol** │ Name: open_web_browser │
│ │ │
│ Alright, the user wants me to do something fairly straightforward: a Google search │ │
│ for "Hello World." Okay, I've got this. My mental checklist kicks in automatically. │ │
│ First, I need to launch the web browser – that's the starting point. Next, I'll │ │
│ navigate directly to Google's main page. Once I'm there, I need to identify the │ │
│ search bar. It's a fundamental element, so it shouldn't be a challenge. Finally, I'll │ │
│ carefully type "Hello World" into the search bar and press "Enter" to initiate the │ │
│ search. Simple and efficient. That covers the request. │
```

### Any other information you'd like to share?

Tested with `google-genai` version `1.64.0`