installer deploy support for on-robot development

When a user is doing development on systemcore, we need a way to deploy code locally. This issue is here to collect requirements and questions/discussion for that. The documentation for the current deploy is at https://github.com/robotpy/robotpy-docs/blob/main/dev/deploy.rst

Eventual products the deploy needs to create:

• standalone python needs to be extracted to /home/systemcore/.python
• a venv with robotpy + requirements needs to be created at /home/systemcore/venv

Questions:

• Should the standalone python tar file be installed on the robot, or the extracted version? What is responsible for putting it there, the ipk? Where is that built?
• Is the venv created from a set of wheels, or is it created and shipped as an ipk?
  • What about vendor wheels + support? How do they get on the robot?
• robotpy-installer needs to exist somewhere
• How much does disk space matter? I think there's only 4GB or so on the systemcore partition, that will only go so far
• What user is this running as?
• If blocks is running these commands, they need to not ask the user questions from stdin -- what's the best way to facilitate this sort of thing?

Ideas:

• My thought is probably the local installer functionality should be run via robotpy installer subcommands
• When we make a robotpy release via robotpy-meta, it runs an install to ensure that everything works. Maybe the wheel bundle should be created by robotpy-meta and made available as a tarfile or something that can be downloaded from github releases or artifactory?
• Resulting deployed environment should be identical for on-bot and off-bot development

Start with the current deployment documentation in robotpy-docs at dev/deploy.rst, then review the listed requirements and open questions in this issue. Trace the proposed robotpy installer subcommands and robotpy-meta release flow; this issue is done when the deployment artifacts, installation ownership, runtime user, noninteractive behavior, and storage constraints have agreed requirements.