Gemini: Support for Interactions API

[ianhawes]

Google recently announced the beta availability of the Interactions API for Gemini.

From the documentation:

The Interactions API is a unified interface for interacting with Gemini models and agents. It simplifies state management, tool orchestration, and long-running tasks.

This appears to be similar in concept to the OpenAI Responses API where there is a desire to move away from the chat completions approach taken by early AI providers. Features include MCP support, stateful conversations, and background processing.

It would be awesome to have support for the Interactions API when using the Gemini provider.