[Dynos & Data] [Education]: Heroku Playground: Ability to explore and learn features

### 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 in General

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

Developer Advocacy at Salesforce foster developer success and lead developers to the future of enterprise application and services development by creating quality content, supporting different platform product teams, and establishing good relationships with the developer community.

We are the bridge between the developers using our products, and the teams building them.

We will be ending the Heroku Free Plans starting November 28. Heroku Free Plans are presently used for much of Heroku’s own feature Developer Advocacy efforts, this can be broken down as GTM efforts, Training via Trailhead Modules, Heroku Certifications and events such as Developer User Groups, TDX and Dreamforce. In these contexts Heroku Free effectively provides a means to explore and learn easily and without the need for financial commitment. This facility is also used for developers exploring SlackApps and LWR (Lightning Web Runtime).

We are considering if an ephemeral playground environment (like Trailhead Playgrounds), potentially scoped to hours of time and/or other contexts such as Trailhead, would aid learning through the above channels without the need to make an upfront commitment. Such a solution would crucially also need to not impact the health of the service nor become a vector of abuse.

This is a product proposal for an ephemeral playground rather than a repository change, and the payload names no files, tests, or implementation entry points. Start by clarifying the required scope, time limits, learning contexts, and abuse protections; done would require an agreed design and an implementation path.

Written by the indexing model from the issue text.