Latest Gemini models including Flash 3.5, Flash 3.6 and Flash 3.7 are fully available and working

### What would you like to be added?

Please bring all latest Gemini models to Gemini CLI so they can be used with full functionality. This includes but is not limited to Flash 3.5, Flash 3.6 and Flash 3.7.

PLEASE AND THANK YOU!

### Why is this needed?

This feature is needed to honor the commitment made by the Gemini team to Gemini Enterprise users per this link at https://developers.googleblog.com/an-important-update-transitioning-gemini-cli-to-antigravity-cli/

>If your organization uses Gemini CLI or our IDE extensions via a Gemini Code Assist Standard or Enterprise license, or if your organization uses Gemini Code Assist for GitHub through Google Cloud, your access remains unchanged. We’ll continue to support Gemini CLI and Gemini Code Assist with access to the latest Gemini models and other updates. Gemini CLI will remain accessible via paid Gemini and Gemini Enterprise Agent Platform API keys. And if you’re excited to try Antigravity CLI, you can use it now with your [Google Cloud projects](http://antigravity.google/blog/google-antigravity-for-enterprises).

### Additional context

_No response_

The issue names no files, tests, or entry points. Start by locating Gemini CLI's model-support and provider integration, then compare the currently available models with the requested latest Gemini models. Done would require all requested models to work with full functionality, but the issue does not define that scope or verification criteria.

Written by the indexing model from the issue text.