Back up existing code

When we copy projects over to a device we may unintentionally overwrite existing user code.

So, we should first read all of the exist files and store them on the phone in a backup. These backups can then accessed as projects of their own in case the user wants them back. "My Projects" maybe. This would be similar to what we do when projects can be modified by the user.

Start by locating the project-copy flow and the existing code for projects that users can modify. Trace how files are read, written, and displayed on the device, then determine how a backup can be stored and exposed as a project under a possible “My Projects” area. Done means existing user code is preserved during copying and can be accessed for restoration.

Written by the indexing model from the issue text.