curl --request GET \
  --url https://api.example.com/v1/dashboard/risk-heatmap \
  --header 'Authorization: Bearer <token>'

{
  "cells": [
    {
      "domain": "<string>",
      "category": "<string>",
      "risk_score": 123,
      "issue_count": 123
    }
  ],
  "updated_at": "<string>",
  "rows": [
    "<string>"
  ],
  "cols": [
    "<string>"
  ]
}