Sync + async clients for Quome sandboxes: create/run/files/preview/lifecycle,
streaming exec over WebSocket (quome[ws]), typed exceptions, key-derived org
resolution. 111 tests, ruff + mypy strict.

Extracted from quome-cloud/quome-fastapi (design + platform APIs live there);
this repo owns the package and its PyPI release so the control-plane monorepo
is not coupled to public publishing.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>