Ajout des partials _stats_head.html et _stats_toolbar.html pour harmoniser les styles et outils des pages de statistiques.

templates/partials/_stats_toolbar.html

@@ -0,0 +1,15 @@
+{# Partials: Shared period toolbar for stats pages #}
+<form method="get" class="toolbar">
+  <div>
+    <label for="p">Période:&nbsp;</label>
+    <select id="p" name="p" onchange="this.form.submit()">
+      {% for opt in period_options %}
+        <option value="{{ opt }}" {% if p == opt %}selected{% endif %}>{{ opt }} jours</option>
+      {% endfor %}
+    </select>
+    <span style="margin-left:8px" class="text-muted">Du {{ start_date }} au {{ end_date }}</span>
+  </div>
+  <div class="text-muted">Mise en cache 15 minutes</div>
+  {% block stats_toolbar_extra %}{% endblock %}
+  {# Keep block for optional extensions on specific pages #}
+</form>