feat(whatsapp): QWEN primary AI backend, Hermes fallback, conversation history, vehicle persistence, demo prompts

- Add QWEN (qwen3.6) as primary AI backend with short system prompt
- Hermes remains as fallback with 45s timeout
- Increase QWEN timeout to 35s, max_tokens to 4000
- Add conversation history loading from whatsapp_messages (last 4 msgs)
- Persist detected vehicle in whatsapp_sessions table
- Add 'limpiar chat' / 'nuevo chat' / 'reset' commands to clear history
- Fix CSS conflict: rename whatsapp chat-panel classes to wa-chat-panel
- Fix JS ID conflicts with chat.js widget (waChatPanel, waChatMessages, etc.)
- Improve no-stock response: conversational with alternatives
- Split search_query by | for multi-part lookups
- Add DEMO_PROMPTS.md and DEMO_PROMPTS_V2.md

pos/static/js/catalog.js

@@ -1382,19 +1382,28 @@
     });
 
     function runSearch(q) {
-        apiFetch(API + '/search?q=' + encodeURIComponent(q) + '&limit=20').then(function (data) {
+        var url = API + '/search?q=' + encodeURIComponent(q) + '&limit=20';
+        if (nav.engine && nav.engine.id_mye) {
+            url += '&mye_id=' + nav.engine.id_mye;
+        }
+        apiFetch(url).then(function (data) {
             if (!data || !data.data || !data.data.length) {
                 searchDropdown.innerHTML = '<div style="padding:var(--space-4);color:var(--color-text-muted);font-size:var(--text-body-sm);">Sin resultados para "' + esc(q) + '"</div>';
                 searchDropdown.classList.add('is-visible');
                 return;
             }
             searchDropdown.innerHTML = data.data.map(function (r) {
+                var isLocal = r.source === 'local_inventory' || (typeof r.id_part === 'string' && r.id_part.indexOf('inv:') === 0);
                 var stockLabel = r.local_stock > 0
                     ? '<span class="stock-badge stock-badge--local" style="margin-left:auto;">Stock: ' + r.local_stock + '</span>'
                     : '';
-                return '<div class="search-result-item" data-part-id="' + r.id_part + '">' +
+                var localBadge = isLocal
+                    ? '<span class="stock-badge stock-badge--local" style="margin-right:4px;background:#4f46e5;">Stock Local</span>'
+                    : '';
+                var oemNum = isLocal ? (r.oem_part_number || r.part_number || '') : (r.oem_part_number || '');
+                return '<div class="search-result-item" data-part-id="' + r.id_part + '" data-name="' + esc(r.name) + '" data-pn="' + esc(oemNum) + '" data-price="' + (r.local_price || '') + '" data-stock="' + (r.local_stock || 0) + '">' +
                     '<div style="flex:1;">' +
-                    '<div class="search-result__oem">' + esc(r.oem_part_number) + '</div>' +
+                    '<div class="search-result__oem">' + localBadge + esc(oemNum) + '</div>' +
                     '<div class="search-result__name">' + esc(r.name) + '</div>' +
                     (r.vehicle_info ? '<div class="search-result__vehicle">' + esc(r.vehicle_info) + '</div>' : '') +
                     '</div>' +
@@ -1408,6 +1417,12 @@
                     searchDropdown.classList.remove('is-visible');
                     var pid = this.dataset.partId;
                     if (typeof pid === 'string' && pid.indexOf('inv:') === 0) {
+                        var info = '💠 Stock Local\n\n' +
+                            'Parte: ' + (this.dataset.pn || 'N/A') + '\n' +
+                            'Nombre: ' + (this.dataset.name || '') + '\n' +
+                            'Precio: $' + (this.dataset.price || '—') + '\n' +
+                            'Stock: ' + (this.dataset.stock || 0) + ' pzas';
+                        alert(info);
                         return;
                     }
                     openPartDetail(parseInt(pid));