`vm run` now covers bare sandbox (no args), workspace sandbox (path),
and workspace+command (path -- cmd) in a single entry point. Replaces
the old print-next-steps-and-exit behaviour: bare and workspace modes
drop into interactive ssh, command mode execs via ssh and propagates
the remote exit code through banger's own exit status.
- path argument is optional; --branch / --from still require a path.
- workspace prep and mise tooling bootstrap only run when a path is
given; command mode skips the bootstrap.
- remote command exit status is wrapped as exitCodeError so main() can
propagate it instead of collapsing every failure to 1.
- README: promote vm run with three-mode examples; demote vm create
to a scripting primitive.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>