Create test tooling for local validation of specialization

We need a way to quickly validate specialization logic for both Windows and Linux locally during development. This needs some design work, but we could:
- have a separate console app just for our "test tooling" that could launch the host in standby mode
- you'd specify a path to an app locally
- have some secondary command that sets the appropriate settings to put the app into standby mode

Windows functionality wouldn't be too hard but Linux would need some work to package and Assign the app to a running Linux image.

The issue names no files, tests, or entry points. First map the existing specialization and host-startup paths for Windows and Linux, then define the console tool's path, standby, and settings commands; done means local validation works on both platforms, including packaging and assigning the app to a running Linux image.

Written by the indexing model from the issue text.