Onboarding checklist

The dashboard checklist tracks four milestones:

1. Add a site.
2. Install the snippet.
3. Create the first experiment.
4. Receive real visitor traffic.

Complete installation before launching a test. Experiments and analytics use the same event stream, so traffic received before a goal or funnel is created can still be analyzed later. A test needs a challenger variant, installed snippet, and primary goal before it can start.