Aggiunge heatmaps first-party (click/scroll) con pagina admin Analytics.

Raccoglie eventi aggregati dietro consenso cookie, senza PII né tracking su admin/regia/live/replay; GA4 resta invariato.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/models/analytics_page_stat.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class AnalyticsPageStat < ApplicationRecord
+  self.table_name = "analytics_page_stats"
+
+  validates :day, :page_path, :device, presence: true
+  validates :device, inclusion: { in: AnalyticsEvent::DEVICES }
+
+  def avg_scroll_pct
+    return 0 if scroll_samples.to_i <= 0
+
+    (scroll_sum_pct.to_f / scroll_samples).round
+  end
+end