Separate instance-level and admin-level dashboard widgets

Users want a clear split between widgets that show data for a single instance (e.g. one brand or location) and widgets that show data at the admin level (e.g. across all instances). So when an admin is in the admin view they see company-wide or cross-instance metrics, and when they're in an instance they see that instance's data only.

Why it matters: Admins and client care need to switch between "my instance" and "the whole company" without confusion about what the numbers represent.