Reading: Debug page for STAR coverage and distributions #2470
Who is this PR for?
What problem does this PR fix?
Shifts in distributions over time or cohorts aren't visible, and while we provide this information in the school overview page and folks use it for decision-making, we don't really help them see wider context. This page if for prototyping that internally first.
What does this PR do?
Screenshot (if adding a client-side feature)
Which features or pages does this PR touch?
Does this PR use tests to help verify we can deploy these changes quickly and confidently?