Lets dev/offline installs keep an already-present global @mosaicstack/gateway
(e.g. a build-from-source `install.sh --dev`) instead of overwriting it with
the registry @latest build during `mosaic wizard` / `mosaic gateway install`.
Refs #675
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RMoEx7hfdFGjUiCHuN1RRi