Mejoras de sesion: estabilizacion, IA, Nexus Yonke y marketplace B2B

- F0 blindaje: Redis/Celery, pg_hba sin trust LAN, secretos a env 600, backups, webhook auth, jobs muertos
- F1 caja: bugs POS, reembolsos al corte, apartados, CFDI, topes de descuento en cotizacion/apartado
- F2/F7 IA de catalogo: autocategorizacion, dedup de SKUs con embeddings, OCR de facturas, descripciones, claves SAT, limpieza de fitment
- F3 IA en el flujo: vision Yonke, preguntas MeLi, venta cruzada, anomalias, sinonimos, busqueda semantica (rerank/embeddings)
- F4/F8 escala y cartera: /metrics+Prometheus+Grafana, pool, score de credito, churn, metricas multi-tenant
- Nexus Yonke (M1-M6): modelo de datos 1-de-1, alta por donador, vitrina publica, MeLi usado, consignacion, garantia por dias, reportes, etiquetas
- Marketplace B2B entre yonkes (catalogo + pedidos cross-tenant)
- Seguridad: auth en /api/admin/* (35 endpoints), alertas por tenant
- Migraciones v4.27/v4.28; timers expire-demos y rollup-metrics

dashboard/catalog-public.html

@@ -23,6 +23,7 @@
           <button data-mode="oem" onclick="setCatalogMode('oem')">OEM</button>
           <button data-mode="local" onclick="setCatalogMode('local')">Local</button>
         </div>
+        <a href="/usados" class="header-back" id="usedPartsLink" title="Partes usadas y reconstruidas">Usados</a>
         <a href="/" class="header-back">&larr; Inicio</a>
         <button class="theme-toggle" onclick="toggleTheme()" id="themeToggle">
           <span id="themeIcon">&#9790;</span>
@@ -86,7 +87,7 @@
     })();
   </script>
 
-  <script src="/catalog-public.js"></script>
+  <script src="/catalog-public.js?v=2"></script>
 
   <!-- AI Chat Widget -->
   <link rel="stylesheet" href="/chat-public.css">

dashboard/catalog-public.js

@@ -27,7 +27,7 @@
     nxPartType: null,      // {slug, name} ← Nexpart part type
 
     region: 'north-america',
-    mode: (localStorage.getItem('catalog_mode') === 'local' ? 'local' : 'oem'),
+    mode: (localStorage.getItem('catalog_mode') === 'oem' ? 'oem' : 'local'),
     page: 1,
     totalPages: 1,
   };
@@ -64,6 +64,7 @@
     state.brand = state.model = state.year = state.engine = null;
     state.level = 'brands';
     loadBrands();
+    waConfig(function () {}); // preload WhatsApp contact config
   };
 
   // ── Region selector (global) ──
@@ -109,6 +110,31 @@
     loadBrands();
   }
 
+  // ── Link a la vitrina de partes usadas del tenant (si existe) ──
+  (function () {
+    var link = document.getElementById('usedPartsLink');
+    if (!link) return;
+    var parts = window.location.hostname.split('.');
+    var sub = (parts.length >= 3) ? parts[0]
+            : (parts.length === 2 && parts[1] === 'localhost') ? parts[0] : '';
+    var reserved = ['www', 'api', 'admin', 'mail', 'staging', 'dev', 'nexus', 'pos', 'app', 'dashboard'];
+    if (reserved.indexOf(sub) !== -1) sub = '';
+    var urlParams2 = new URLSearchParams(window.location.search);
+    var tenant = urlParams2.get('tenant') || sub;
+    if (!tenant) return;
+    fetch('/api/public/used-parts?per_page=1&tenant=' + encodeURIComponent(tenant))
+      .then(function (r) { return r.ok ? r.json() : null; })
+      .then(function (d) {
+        if (d && d.total > 0) {
+          link.href = '/usado/' + encodeURIComponent(d.tenant.subdomain || tenant);
+          link.textContent = 'Usados (' + d.total + ')';
+        } else {
+          link.style.display = 'none';
+        }
+      })
+      .catch(function () { link.style.display = 'none'; });
+  })();
+
   // Enter on search
   // ── Smart search detector ──
   function detectQueryType(raw) {
@@ -729,6 +755,7 @@
           }
 
           html += '<button class="part-detail-btn" onclick="openDetail(' + p.id_part + ')">Ver detalle y alternativas</button>';
+          html += waQuoteButtonHtml(p);
           html += '</div>';
           if (p.image_url) {
             html += '<img class="part-img" src="' + esc(p.image_url) + '" alt="" loading="lazy" onerror="this.style.display=\'none\'">';
@@ -782,6 +809,26 @@
     content.innerHTML = html;
   }
 
+  // ── WhatsApp quote button ──
+  var _waConfig = null;
+  function waConfig(cb) {
+      if (_waConfig) return cb(_waConfig);
+      fetch('/api/public/contact-config').then(function (r) { return r.json(); })
+          .then(function (d) { _waConfig = d || { enabled: false }; cb(_waConfig); })
+          .catch(function () { _waConfig = { enabled: false }; cb(_waConfig); });
+  }
+
+  function waQuoteButtonHtml(p) {
+      var cfg = _waConfig;
+      if (!cfg || !cfg.enabled || !cfg.wa_number) return '';
+      var text = 'Hola, me interesa cotizar esta pieza:%0A%0A*OEM:* ' + encodeURIComponent(p.oem_part_number || '') +
+          '%0A*Descripción:* ' + encodeURIComponent(p.name || '');
+      if (p.vehicle_info) text += '%0A*Vehículo:* ' + encodeURIComponent(p.vehicle_info);
+      return '<a class="btn-wa-quote" target="_blank" rel="noopener" href="https://wa.me/' + cfg.wa_number + '?text=' + text + '"' +
+          ' style="display:inline-flex;align-items:center;gap:8px;margin-top:var(--space-4);padding:12px 20px;border-radius:var(--radius-md);background:#25D366;color:#fff;text-decoration:none;font-weight:600;">' +
+          'Cotizar por WhatsApp</a>';
+  }
+
   // ── Part detail ──
   function renderDetail(d, body) {
     if (!d || !d.part) {
@@ -831,7 +878,7 @@
       html += '</tbody></table></div>';
     }
 
-    body.innerHTML = html;
+    waConfig(function () { html += waQuoteButtonHtml(p); body.innerHTML = html; });
   }
 
   // ── Helpers ──

dashboard/nav.js

@@ -31,14 +31,14 @@
     }
 
     var navLinks = [
-        { label: 'Demo', href: '/demo' },
-        { label: 'Tienda', href: '/tienda' },
+        { label: 'Demo', href: '/demo.html' },
+        { label: 'Tienda', href: '/tienda.html' },
         { label: 'Cat\u00e1logo', href: '/index.html' },
-        { label: 'Captura', href: '/captura' },
-        { label: 'POS', href: '/pos' },
-        { label: 'Cuentas', href: '/cuentas' },
-        { label: 'Bodega', href: '/bodega' },
-        { label: 'Admin', href: '/admin' }
+        { label: 'Captura', href: '/captura.html' },
+        { label: 'POS', href: '/pos/login' },
+        { label: 'Cuentas', href: '/cuentas.html' },
+        { label: 'Bodega', href: '/bodega.html' },
+        { label: 'Admin', href: '/admin.html' }
     ];
 
     var linksHTML = navLinks.map(function (link) {