The sandbox handlers describe, list, download, upload, open a terminal
and build SSH and VNC access on the `Arc<dyn Sandbox>` the server attaches
to the run's record, with paths resolved against the recorded working
directory. Run Files holds the handle beside that directory and runs its
git through the driver's git facet and Fabro's exec policy;
fabro-workflow's sandbox git takes the same pair, and its
`GitCommandError` carries the driver's error. Run deletion deletes by id
through the provider scoped to the run's `petri.run` label, so a foreign
sandbox is refused and a designated host directory is left in place. Ask
Fabro wraps the attached, running handle. The legacy access shim is gone.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>