Admin analytics: heatmap per device, anteprima staff e analisi costi.

Separa heatmap mobile/desktop, opt-out analytics per operatori, dashboard costi con KPI e trend mensili.

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

backend/app/views/admin/cost_entries/_form.html.erb

@@ -0,0 +1,34 @@
+<%= form_with model: @entry, url: url, method: method, local: true, class: "admin-filter-form" do |f| %>
+  <div class="admin-filter-grid">
+    <label class="admin-filter-field">
+      <span><%= t("admin.costs.entries.month") %></span>
+      <%= text_field_tag "platform_cost_entry[month]",
+            @entry.month&.strftime("%Y-%m"),
+            type: "month",
+            required: true %>
+    </label>
+    <label class="admin-filter-field">
+      <span><%= t("admin.costs.entries.label") %></span>
+      <%= f.text_field :label, required: true, maxlength: 120 %>
+      <span class="muted admin-table-sub"><%= t("admin.costs.entries.label_hint") %></span>
+    </label>
+    <label class="admin-filter-field">
+      <span><%= t("admin.costs.entries.amount") %></span>
+      <%= number_field_tag "platform_cost_entry[amount_euros]",
+            (@entry.amount_cents.to_f / 100.0 if @entry.amount_cents.present?),
+            step: 0.01,
+            min: 0.01,
+            required: true %>
+    </label>
+    <label class="admin-filter-field" style="grid-column: span 2;">
+      <span><%= t("admin.costs.entries.notes") %></span>
+      <%= f.text_area :notes, rows: 3 %>
+    </label>
+  </div>
+  <div class="admin-filter-actions">
+    <%= f.submit t("admin.costs.entries.save"), class: "admin-btn admin-btn--primary admin-btn--sm" %>
+    <%= link_to t("admin.costs.entries.cancel"),
+          admin_costs_path(month: @entry.month&.strftime("%Y-%m")),
+          class: "admin-btn admin-btn--outline admin-btn--sm" %>
+  </div>
+<% end %>