I'm building a Flutter app and want to integrate with the Android built-in Gemini Assistant (not the Gemini API) so the assistant can fetch and display content (like a list of songs) and control in-app actions (like play/pause), similar to how the Spotify app works with Gemini/Google Assistant.

I'm specifically looking for the system-level Assistant integration (App Actions, App Functions SDK, Built-in Intents, or similar), not a Gemini API based chatbot inside the app.

What I've found so far:

• App Actions documentation seems outdated/deprecated in places

• No clear end-to-end guide for Flutter apps

• Unsure if this is restricted to select partners or open to all developers

My questions:

1. Is there current official documentation for integrating with the system Gemini Assistant for content fetch/playback actions?

2. Which APIs/SDKs are relevant now (App Actions vs App Functions vs Built-in Intents)?

3. Is this available for third-party/Flutter apps, or only Google partners?

4. Since Flutter doesn't have native support for this, how should this be bridged via platform channels?

5. Can the system Gemini Assistant keep the conversation alive and ask follow-up questions to the user (multi-turn interaction) when invoked from a third-party app, or is it limited to single-shot command/intent execution?

Any guidance, sample projects, or links to current documentation would be very helpful.