Fix: re-raise original docker exception in Sandbox.start error handlers

[laohuan12138]

Fixes #74

Summary

Sandbox.start() re-raised docker errors by constructing a new exception without a message:

except ImageNotFound as exc:
    raise ImageNotFound from exc   # ImageNotFound() → APIError() → TypeError
except NotFound as exc:
    raise NotFound from exc

docker.errors.ImageNotFound/NotFound inherit APIError, whose __init__ requires message. The no-arg construction raises TypeError: APIError.__init__() missing 1 required positional argument: 'message', masking the real error — e.g. when xoxruns/sandboxed_kali is missing locally, the user sees this TypeError instead of ImageNotFound.

Change

Re-raise the original exception in both handlers:

except ImageNotFound as exc:
    logger.error("Image not found %s", container_image)
    raise exc
except NotFound as exc:
    logger.error("Docker error: %s", exc.explanation)
    raise exc

Verification

• Pre-fix: TypeError: APIError.__init__() missing 1 required positional argument: 'message' reproduced with docker SDK 7.1.0 (both with real SDK and the exact class hierarchy).
• Post-fix: the original docker.errors.ImageNotFound propagates with its explanation intact.
• Live check: with the sandbox image pulled, the CLI no longer reports the sandbox-creation failure.

Note: full pytest suite not run here (dependencies not installed in this environment); the change is limited to the two exception-handler lines and does not alter normal flow.

[xoxruns]

Just saw you PR. Gonna check this out to try and reproduce the error ! thank you @laohuan12138