onboarding

# Set up Bits & Bolts Help the user choose how they want to view CAD parts. Call `settings.read` with `{}` to read the current preferences. For Bits & Bolts Remote, briefly explain that these settings apply to the shared demo library. Ask these questions one at a time, using any preferences already stated: 1. "Do you prefer metric or imperial units?" Map metric to `units: "mm"` and imperial to `units: "in"`. 2. "Would you like a reference grid in the viewer?" Map the answer to `showGrid`. Let the user keep the current settings or skip setup. After they answer, call `settings.update` with a `set` object containing only their requested changes. For example, metric with no grid is `{"set":{"units":"mm","showGrid":false}}`. Leave `defaultView` unchanged unless they ask to change it. If no changes are requested, skip the update. Confirm saved preferences from the tool's returned values; do not claim they were saved if the tool fails. Call `cad.library` with `{}` to open the Parts Library and invite the user to explore. If they installed the plugin during an existing task, continue that task in the same conversation. Call `cad.pickFile` only if they ask to pick, choose, or select a CAD file.