[FR] Allow users to get AI Max or upgrade plans in mobile app

### Description

Users can't upgrade or purchase AI Max within the mobile app. Since direct purchase links are not allowed, we can:
1. Enable upgrades via play stores.
2. Provide a link in the app message directing users to a product doc with instructions on upgrading via the web or desktop app.

Source from [google play](https://play.google.com/console/u/0/developers/7723367747650384474/app/4974350768997726488/user-feedback/review-details?reviewId=f10dd553-46d9-414d-803f-36d83987114e&corpus=PUBLIC_REVIEWS)
> When I want to create an image, this message appears: "AI image responses have been exhausted from your workspace. Please ask your workspace admin to purchase AI Max."

### Impact

Improves user experience and conversion rates

### Additional Context

_No response_

Start by tracing the mobile app's message shown when workspace AI image responses are exhausted, then inspect the upgrade and purchase flows. Use the Google Play feedback and the issue's two proposed approaches as requirements. Done means mobile users can upgrade or purchase AI Max through an allowed store flow, or receive a product-document link with clear web or desktop instructions.

Written by the indexing model from the issue text.