You're mistaken - ghost is not a "service". It is a CLI tool. And [0] is precisely how GH Actions runners are used everyday. It's not something other.

ghost doesn't "abuses the subsidised free tier". When you run ghost it uses your free minutes, not someone else's.

In reality, the % of Actions total global minutes that would be used for these hybrid "human and/or agent real-time" workflow where you drop into a machine would be tiny compared to the bulk p95 which is automated workflows for CI.

This is for where you want to drop into a consistent environment and get into the weeds or have your agent debug what's going on, or use the security isolation to develop safely in Actions cloud rather than rooting your laptop with an agent perhaps.