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/views/admin/analytics/show.html.erb

@@ -0,0 +1,115 @@
+<% content_for :body_class, "admin-body" %>
+
+<div class="admin-page-head admin-session-head">
+  <div>
+    <p class="muted admin-page-sub">
+      <%= link_to t("admin.analytics.show.back"), admin_analytics_path(from: @filters[:from], to: @filters[:to], device: @filters[:device]) %>
+    </p>
+    <h2 class="admin-page-title"><%= t("admin.analytics.show.title") %></h2>
+    <p><code class="admin-mono"><%= @page_path %></code></p>
+  </div>
+</div>
+
+<div class="panel admin-sessions-filters">
+  <%= form_with url: admin_analytics_page_path, method: :get, local: true, class: "admin-filter-form" do %>
+    <%= hidden_field_tag :page_path, @page_path %>
+    <div class="admin-filter-grid">
+      <label class="admin-filter-field">
+        <span><%= t("admin.analytics.filters.from") %></span>
+        <%= date_field_tag :from, @filters[:from] %>
+      </label>
+      <label class="admin-filter-field">
+        <span><%= t("admin.analytics.filters.to") %></span>
+        <%= date_field_tag :to, @filters[:to] %>
+      </label>
+      <label class="admin-filter-field">
+        <span><%= t("admin.analytics.filters.device") %></span>
+        <%= select_tag :device,
+              options_for_select(
+                [[t("admin.analytics.filters.any"), ""]] + AnalyticsEvent::DEVICES.map { |d| [d, d] },
+                @filters[:device]
+              ) %>
+      </label>
+    </div>
+    <div class="admin-filter-actions">
+      <%= submit_tag t("admin.analytics.filters.apply"), class: "admin-btn admin-btn--primary admin-btn--sm" %>
+    </div>
+  <% end %>
+</div>
+
+<div class="admin-session-grid">
+  <section class="panel">
+    <h3><%= t("admin.analytics.show.summary") %></h3>
+    <dl class="admin-kv">
+      <div>
+        <dt><%= t("admin.analytics.index.table.pageviews") %></dt>
+        <dd><%= @pageviews %></dd>
+      </div>
+      <div>
+        <dt><%= t("admin.analytics.index.table.clicks") %></dt>
+        <dd><%= @cells.values.sum %></dd>
+      </div>
+      <div>
+        <dt><%= t("admin.analytics.index.table.avg_scroll") %></dt>
+        <dd><%= @avg_scroll %>%</dd>
+      </div>
+      <div>
+        <dt><%= t("admin.analytics.index.table.max_scroll") %></dt>
+        <dd><%= @max_scroll %>%</dd>
+      </div>
+    </dl>
+  </section>
+
+  <section class="panel" style="grid-column: span 2;">
+    <h3><%= t("admin.analytics.show.scroll_depth") %></h3>
+    <div class="admin-scroll-bar" aria-hidden="true">
+      <div class="admin-scroll-bar__avg" style="width: <%= @avg_scroll %>%"></div>
+      <div class="admin-scroll-bar__max" style="left: <%= @max_scroll %>%"></div>
+    </div>
+    <p class="muted admin-table-sub">
+      <%= t("admin.analytics.show.scroll_hint", avg: @avg_scroll, max: @max_scroll) %>
+    </p>
+  </section>
+</div>
+
+<section class="panel">
+  <h3><%= t("admin.analytics.show.heatmap_title") %></h3>
+  <% if @cells.any? %>
+    <div class="admin-heatmap-wrap">
+      <canvas
+        id="admin-heatmap"
+        class="admin-heatmap"
+        width="800"
+        height="1200"
+        data-grid="<%= @grid %>"
+        data-max="<%= @max_clicks %>"
+        data-cells="<%= @cells.map { |(x, y), c| { x: x, y: y, c: c } }.to_json %>"
+      ></canvas>
+    </div>
+    <script>
+    (function () {
+      var canvas = document.getElementById("admin-heatmap");
+      if (!canvas) return;
+      var grid = parseInt(canvas.getAttribute("data-grid"), 10) || 40;
+      var max = parseInt(canvas.getAttribute("data-max"), 10) || 1;
+      var cells = [];
+      try { cells = JSON.parse(canvas.getAttribute("data-cells") || "[]"); } catch (e) { cells = []; }
+      var ctx = canvas.getContext("2d");
+      var cw = canvas.width;
+      var ch = canvas.height;
+      ctx.fillStyle = "#0d0d12";
+      ctx.fillRect(0, 0, cw, ch);
+      var cellW = cw / grid;
+      var cellH = ch / grid;
+      cells.forEach(function (cell) {
+        var intensity = Math.min(1, cell.c / max);
+        var alpha = 0.15 + intensity * 0.75;
+        ctx.fillStyle = "rgba(229, 57, 53, " + alpha + ")";
+        ctx.fillRect(cell.x * cellW, cell.y * cellH, cellW + 0.5, cellH + 0.5);
+      });
+    })();
+    </script>
+  <% else %>
+    <p class="empty"><%= t("admin.analytics.show.no_clicks") %></p>
+  <% end %>
+</section>