fix(classrooms): blindar vistas presenciales y virtuales sin aulas + feat(admin): reinicializacion de sistema con clave de admin

frontend/views/classrooms/list.html

@@ -268,7 +268,7 @@
 </div>
 
 <!-- Grilla y Tabla de Aulas Físicas -->
-{% if classrooms and classrooms.items %}
+{% if classrooms and classrooms.items and (classrooms.items|length > 0) %}
 
 <!-- 1. VISTA DE TARJETAS / MOSAICO -->
 <div data-view-context="classrooms" data-view-container="cards">
@@ -708,7 +708,7 @@
 </div>
 
 <!-- Catálogo de Aulas Virtuales por Comisión -->
-{% if virtual_rooms %}
+{% if virtual_rooms and (virtual_rooms|length > 0) %}
 <div class="row g-3">
     {% for room in virtual_rooms %}
     <div class="col-xxl-3 col-xl-3 col-lg-4 col-md-6 col-sm-12 mb-2">
@@ -1008,7 +1008,7 @@
 {% endif %}
 
 <!-- Modales de Eliminación de Aulas Físicas -->
-{% if classrooms and classrooms.items %}
+{% if classrooms and classrooms.items and (classrooms.items|length > 0) %}
 {% for classroom in classrooms.items %}
 <div class="modal fade text-start" id="modalDeleteClassroom{{ classroom.id }}" tabindex="-1" aria-hidden="true">
     <div class="modal-dialog modal-dialog-centered">