Add stats endpoint

spec/requests/api/v1/stats_spec.rb

@@ -0,0 +1,21 @@
+require 'rails_helper'
+
+RSpec.describe "Api::V1::Stats", type: :request do
+  describe "GET /stats" do
+    it "returns summary stats" do
+      alerts(:two).update!(park_code: parks(:one).code)
+
+      get api_v1_stats_url
+
+      expect(response).to have_http_status(:success)
+      expect(response.parsed_body).to match(
+        park_count: 2,
+        alert_count: 2,
+        most_alerts: {
+          park_code: "crla",
+          alert_count: 2
+        }
+      )
+    end
+  end
+end