feat: add admin views, a booking horizon and confirmation modals

Co-Authored-By: Claude Opus 5 <[email protected]>

templates/dashboard/index.html.twig

@@ -47,6 +47,23 @@
             </div>
             <p class="text-sm text-gray-500 pb-4">Alle Termine und Serien verwalten.</p>
         </a>
+
+        {#
+            The header is deliberately not navigation, so the dashboard is the only place an
+            admin screen can be reached from.
+        #}
+        {% if is_granted('ROLE_ADMIN') %}
+            <a href="{{ path('app_admin_booking') }}"
+               class="group flex flex-col rounded-md border border-gray-200 p-6 hover:border-primary hover:bg-gray-50">
+                <div class="flex items-center gap-3 pb-2">
+                    {{ ux_icon('lucide:shield-check', { class: 'h-6 w-6 shrink-0 text-primary' }) }}
+                    <span class="text-lg font-bold">Verwaltung</span>
+                </div>
+                <p class="text-sm text-gray-500 pb-4">
+                    Buchungen aller Mitarbeitenden einsehen und ggf. freigeben.
+                </p>
+            </a>
+        {% endif %}
     </div>
 
     <h2 class="pt-10">Als Nächstes</h2>