feat(dashboard): cards colapsables en Analytics Dashboard

- Convertir 9 cards a estructura colapsable con Bootstrap 5 Collapse
- Headers fuera de cards como botones clickeables
- Cards contraídos por defecto para reducir scroll
- Añadir animación de rotación del chevron (180°)
- Ajustar selector JS de loading overlay a .collapsible-section
- CSS para estados hover, focus y bordes redondeados

Cards modificados:
1. CTR 0% (collapse-ctr-zero)
2. Quick Wins (collapse-quick-wins)
3. Contenido Decadencia (collapse-decay)
4. Contenido Estrella (collapse-star)
5. Infraposicionados (collapse-infrapos)
6. Click Distribution (collapse-click-dist)
7. Top Búsquedas (collapse-top-searches)
8. Top Clicks (collapse-top-clicks)
9. Sin Resultados (collapse-zero-results)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

admin/assets/dashboard.css

@@ -212,6 +212,89 @@ body .card {
     font-size: 0.875rem;
 }
 
+/* =================================================================
+   Collapsible Cards
+   ================================================================= */
+
+.dashboard-analytics-wrap .collapsible-section {
+    margin-bottom: 1rem;
+}
+
+.dashboard-analytics-wrap .collapsible-header {
+    cursor: pointer;
+    transition: all 0.2s ease;
+    text-align: left;
+    font-family: 'Poppins', -apple-system, BlinkMacSystemFont, sans-serif;
+}
+
+.dashboard-analytics-wrap .collapsible-header:hover {
+    filter: brightness(1.1);
+}
+
+.dashboard-analytics-wrap .collapsible-header:focus {
+    outline: none;
+    box-shadow: 0 0 0 2px rgba(255, 134, 0, 0.5);
+}
+
+/* Chevron rotation */
+.dashboard-analytics-wrap .collapse-chevron {
+    transition: transform 0.3s ease;
+    font-size: 1rem;
+}
+
+.dashboard-analytics-wrap .collapsible-header:not(.collapsed) .collapse-chevron {
+    transform: rotate(180deg);
+}
+
+/* Header bordes */
+.dashboard-analytics-wrap .collapsible-header {
+    border-radius: 0.375rem;
+}
+
+.dashboard-analytics-wrap .collapsible-header:not(.collapsed) {
+    border-radius: 0.375rem 0.375rem 0 0;
+}
+
+/* Card sin borde superior cuando está expandido */
+.dashboard-analytics-wrap .collapsible-section .card {
+    border-top-left-radius: 0;
+    border-top-right-radius: 0;
+    border-top: none;
+}
+
+/* Loading en collapsible section */
+.dashboard-analytics-wrap .collapsible-section.is-loading-table {
+    position: relative;
+    pointer-events: none;
+}
+
+.dashboard-analytics-wrap .collapsible-section.is-loading-table::after {
+    content: '';
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    background: rgba(255, 255, 255, 0.7);
+    z-index: 10;
+    border-radius: 0.375rem;
+}
+
+.dashboard-analytics-wrap .collapsible-section.is-loading-table::before {
+    content: '';
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    width: 24px;
+    height: 24px;
+    margin: -12px 0 0 -12px;
+    border: 3px solid #f3f3f3;
+    border-top: 3px solid #FF8600;
+    border-radius: 50%;
+    z-index: 11;
+    animation: spin 0.8s linear infinite;
+}
+
 /* =================================================================
    Responsive
    ================================================================= */

admin/assets/dashboard.js

@@ -99,10 +99,10 @@
             return;
         }
 
-        // Find the card container and add loading state (keeps size, shows overlay)
-        var card = tbody.closest('.card');
-        if (card) {
-            card.classList.add('is-loading-table');
+        // Find the collapsible section container and add loading state (keeps size, shows overlay)
+        var section = tbody.closest('.collapsible-section');
+        if (section) {
+            section.classList.add('is-loading-table');
         }
 
         // Build form data
@@ -157,8 +157,8 @@
                 tbody.innerHTML = html;
 
                 // Remove loading state
-                if (card) {
-                    card.classList.remove('is-loading-table');
+                if (section) {
+                    section.classList.remove('is-loading-table');
                 }
 
                 // Update pagination
@@ -167,16 +167,16 @@
                     bindPaginationEvents(paginationDiv, tableId);
                 }
             } else {
-                if (card) {
-                    card.classList.remove('is-loading-table');
+                if (section) {
+                    section.classList.remove('is-loading-table');
                 }
                 showErrorMessage('Error al cargar datos');
                 console.error('AJAX error:', result);
             }
         })
         .catch(function(error) {
-            if (card) {
-                card.classList.remove('is-loading-table');
+            if (section) {
+                section.classList.remove('is-loading-table');
             }
             console.error('Fetch error:', error);
             showErrorMessage('Error de conexión');