White label heroku app

### Required Terms

- [X] I agree to follow this project's [Code of Conduct](https://github.com/heroku/roadmap/blob/main/CODE_OF_CONDUCT.md)
- [X] I have read and accept the [Salesforce Program Agreement](https://www.salesforce.com/company/program-agreement/)

### What service(s) is this request for?

Heroku/Salesforce

### Tell us about what you're trying to solve. What challenges are you facing?

I would like to sell an Heroku app as a service to customers that care about security. Thus as an app provider I should not have access to the app data or logs. The customer should be able to have basic control the app on it's own but no access to any code nor console.

Here is how it would work, somebody could purchase my app on heroku.

They purchase directly from Heroku, with the same experience as an Heroku button.
They can choose how they scale the app. (number of dynos), as an app provider I don't have any control there.
They can control the environment variables, as an app provider I don't have any control
They have access to their logs, as an app provider I don't.
They can't open a one-off script, as an app provider I can't either.
They are billed directly by heroku.
I get paid by heroku based on the usage of my app.
The customer can see when an update is available and can choose to auto-update (and maybe rollback)

This is working well for stateless app that provide a service like stateless computation.

This is great from a security perspective, I don't have access to my customer data or runtime but I can still provide the code that is ran by Heroku.

This would be a quick way to replace salesforce functions and allow ISV to provide heroku capabilities to salesforce customers.
(The client could quickly have an heroku app deployed and linked to their salesforce instance)

I hope I am being clear here.