This commit introduces two new commands to the `borg` CLI:
- `borg compile`: Compiles a `Borgfile` into a "Terminal Isolation
Matrix" (`.matrix` file). The `Borgfile` format is a simple text file
with `ADD <src> <dest>` instructions.
- `borg run`: Executes a `.matrix` file using `runc`. The command
unpacks the matrix into a temporary directory and then executes `runc
run`.
This commit also adds comprehensive tests for the new commands and the
`pkg/matrix` package, significantly increasing the overall test
coverage. The tests for the `run` command use a mocking pattern to
avoid environment dependencies.
5711b6c13c