feat: sidebar con buscador de módulos e icono de configuración

- Icono de engranaje (⚙) en cabecera del sidebar → lab_configuracion.php
- Buscador de texto que filtra ítems del menú en tiempo real
- Al borrar la búsqueda restaura el estado colapsado guardado
- CSS integrado en el mismo componente

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

shared/components/sidebar.php

@@ -103,8 +103,20 @@ $_base = defined('APP_URL') ? rtrim(APP_URL, '/') : '';
 <nav class="sidebar" id="erp-sidebar">
 
     <div class="sidebar-header">
-        <h4><i class="<?= htmlspecialchars($_sidebar_icon, ENT_QUOTES, 'UTF-8') ?>"></i>
-            <?= htmlspecialchars($_sidebar_title, ENT_QUOTES, 'UTF-8') ?></h4>
+        <h4 style="flex:1;min-width:0">
+            <i class="<?= htmlspecialchars($_sidebar_icon, ENT_QUOTES, 'UTF-8') ?>"></i>
+            <?= htmlspecialchars($_sidebar_title, ENT_QUOTES, 'UTF-8') ?>
+        </h4>
+        <a href="<?= $_base ?>/lab_configuracion.php" class="sb-config-btn" title="Configuración">
+            <i class="fas fa-gear"></i>
+        </a>
+    </div>
+
+    <!-- Buscador de menú -->
+    <div class="sb-search-wrap">
+        <i class="fas fa-search sb-search-icon"></i>
+        <input type="text" id="sbSearch" class="sb-search" placeholder="Buscar módulo…"
+               oninput="sbFilter(this.value)" autocomplete="off">
     </div>
 
     <ul class="sidebar-menu" id="sb-menu">
@@ -211,6 +223,48 @@ if (class_exists('ModuleRegistry', false)) {
 </nav>
 
 <style>
+/* ── Botón config en header ─────────────────────────── */
+.sidebar-header { display:flex; align-items:center; gap:10px; }
+.sb-config-btn {
+    color: rgba(255,255,255,.65);
+    font-size: 1rem;
+    padding: 4px 6px;
+    border-radius: 6px;
+    transition: color .15s, background .15s;
+    flex-shrink: 0;
+    line-height: 1;
+}
+.sb-config-btn:hover { color:#fff; background:rgba(255,255,255,.15); }
+
+/* ── Buscador de menú ───────────────────────────────── */
+.sb-search-wrap {
+    position: relative;
+    padding: 10px 14px 6px;
+    flex-shrink: 0;
+}
+.sb-search-icon {
+    position: absolute;
+    left: 24px;
+    top: 50%;
+    transform: translateY(-30%);
+    color: rgba(255,255,255,.45);
+    font-size: .75rem;
+    pointer-events: none;
+}
+.sb-search {
+    width: 100%;
+    background: rgba(255,255,255,.12);
+    border: 1px solid rgba(255,255,255,.18);
+    border-radius: 8px;
+    color: #fff;
+    padding: 6px 10px 6px 28px;
+    font-size: .8rem;
+    outline: none;
+    transition: background .2s, border-color .2s;
+}
+.sb-search::placeholder { color: rgba(255,255,255,.45); }
+.sb-search:focus { background: rgba(255,255,255,.2); border-color: rgba(255,255,255,.4); }
+
 /* ── Acordeón de categorías ─────────────────────────── */
 .sidebar-section {
     display: flex;
@@ -285,6 +339,54 @@ if (class_exists('ModuleRegistry', false)) {
         setCollapsed(arr);
     };
 
+    // ── Buscador de menú ─────────────────────────────────────────
+    window.sbFilter = function(q) {
+        q = q.trim().toLowerCase();
+        var menu = document.getElementById('sb-menu');
+        if (!menu) return;
+
+        if (!q) {
+            // Restaurar estado guardado
+            menu.querySelectorAll('.sb-group').forEach(function(g) {
+                g.style.display = '';
+            });
+            menu.querySelectorAll('.sidebar-section').forEach(function(s) {
+                s.style.display = '';
+            });
+            // Re-aplicar estado colapsado
+            var collapsed = getCollapsed();
+            menu.querySelectorAll('.sb-group').forEach(function(group) {
+                var section = document.querySelector('[data-cat="' + group.id + '"]');
+                var hasActive = !!group.querySelector('.nav-link.active');
+                var isCol = !hasActive && collapsed.indexOf(group.id) !== -1;
+                if (section) applyState(group, section, isCol, false);
+            });
+            return;
+        }
+
+        // Mostrar todos expandidos y filtrar por texto
+        menu.querySelectorAll('.sb-group').forEach(function(g) {
+            var links     = g.querySelectorAll('.nav-link');
+            var anyMatch  = false;
+            links.forEach(function(a) {
+                var txt = a.textContent.toLowerCase();
+                var show = txt.includes(q);
+                a.parentElement.style.display = show ? '' : 'none';
+                if (show) anyMatch = true;
+            });
+            // Mostrar/ocultar grupo completo
+            g.style.display = anyMatch ? '' : 'none';
+            g.style.maxHeight = '2000px';
+            g.style.opacity   = '1';
+            g.classList.remove('collapsed');
+            var section = document.querySelector('[data-cat="' + g.id + '"]');
+            if (section) {
+                section.style.display = anyMatch ? '' : 'none';
+                section.classList.remove('collapsed');
+            }
+        });
+    };
+
     // Inicializar al cargar
     document.addEventListener('DOMContentLoaded', function () {
         var collapsed = getCollapsed();