feat: complete session — catalog, marketplace, WhatsApp, peer-to-peer, install scripts

Major features:
- Pixel-Perfect glassmorphism design (landing + POS + public catalog)
- OEM/Local catalog toggle with Nexpart taxonomy (14 groups, 108 subgroups, 558 part types)
- Marketplace B2B Phase 1 (bodegas, POs, status machine, WA+email notifications)
- Peer-to-peer inventory (multi-instance, LAN discovery)
- WhatsApp: photo→Vision AI, voice→Whisper, conversational quotations
- Smart unified search (VIN/plate/part_number/keyword auto-detect)
- Shop Supplies tab (vehicle-independent parts)
- Chatbot AI fallback chain (5 models) + response cache
- CSV inventory import tool + setup_instance.sh installer
- Tablet-responsive CSS + sidebar toggle
- Filters, export CSV, employee edit, business data save
- Quotation system (WA→POS) with auto-print on confirmation
- Live stats on landing page

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pos/templates/inventory.html

@@ -6,6 +6,7 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Inventario — Nexus Autoparts POS</title>
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
+  <link rel="stylesheet" href="/pos/static/css/pos-glass.css" />
   <link rel="manifest" href="/pos/static/pwa/manifest.json" />
   <meta name="theme-color" content="#F5A623" />
 
@@ -1468,9 +1469,9 @@
           <h1 class="page-header__title">Inventario</h1>
         </div>
         <div class="page-header__actions">
-          <button class="btn btn--ghost" onclick="alert('Exportar: próximamente')">
+          <button class="btn btn--ghost" onclick="exportVisibleTableCSV('inventario')">
             <svg viewBox="0 0 24 24"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="7 10 12 15 17 10"/><line x1="12" y1="15" x2="12" y2="3"/></svg>
-            Exportar
+            Exportar CSV
           </button>
           <button class="btn btn--ghost" onclick="loadItems(1,'')">
             <svg viewBox="0 0 24 24"><polyline points="23 4 23 10 17 10"/><path d="M20.49 15a9 9 0 1 1-.38-4.93"/></svg>
@@ -1585,14 +1586,24 @@
               <option>OK</option><option>Bajo</option><option>Sobrestock</option>
             </select>
             <div class="toolbar__spacer"></div>
-            <button class="btn btn--ghost btn--sm">
+            <button class="btn btn--ghost btn--sm" onclick="openInventoryFilters(this)">
               <svg viewBox="0 0 24 24"><polygon points="22 3 2 3 10 12.46 10 19 14 21 14 12.46 22 3"/></svg>
               Filtros
             </button>
-            <button class="btn btn--ghost btn--sm">
-              <svg viewBox="0 0 24 24"><path d="M3 9l9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/><polyline points="9 22 9 12 15 12 15 22"/></svg>
-              Columnas
-            </button>
+            <script>
+            function openInventoryFilters(btn) {
+                var table = document.querySelector('table');
+                if (!table) { showToast('Carga el inventario primero', 'warn'); return; }
+                var brands = getUniqueColumnValues(table, 3);  // brand column
+                var categories = getUniqueColumnValues(table, 4); // category column
+                var statuses = getUniqueColumnValues(table, 5);   // stock status column
+                toggleFilterPanel(btn, [
+                    {label: 'Marca', column: 3, values: brands},
+                    {label: 'Categoría', column: 4, values: categories},
+                    {label: 'Estado Stock', column: 5, values: statuses},
+                ]);
+            }
+            </script>
             <button class="btn btn--primary btn--sm" onclick="showCreateModal()">
               <svg viewBox="0 0 24 24"><line x1="12" y1="5" x2="12" y2="19"/><line x1="5" y1="12" x2="19" y2="12"/></svg>
               Nuevo Producto
@@ -2097,6 +2108,7 @@
 
   <script src="/pos/static/js/i18n.js"></script>
   <script src="/pos/static/js/app-init.js"></script>
+  <script src="/pos/static/js/pos-utils.js"></script>
   <script src="/pos/static/js/sidebar.js"></script>
   <script src="/pos/static/js/inventory.js"></script>
   <script src="/pos/static/js/offline-banner.js"></script>