feat(voice): implementa voz y TTS en chats POS y dashboard

- Agrega TTS (speechSynthesis) a chat.js del POS para leer respuestas IA
- Copia lógica de voz completa (STT + TTS) a dashboard/chat-public.js
- Extiende estilos TTS en chat.css y chat-public.css
- Agrega chat widget a 13 templates POS que no lo tenían
- Corrige duplicado de chat.css en diagrams.html
- Minifica assets actualizados
- 73/73 tests pasan

pos/static/css/chat.css

@@ -104,6 +104,27 @@
 
 .chat-header-close:hover { opacity: 1; }
 
+.chat-header-actions {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+}
+
+.chat-tts-toggle {
+  background: none;
+  border: none;
+  color: #fff;
+  font-size: 1rem;
+  cursor: pointer;
+  padding: var(--space-1);
+  line-height: 1;
+  opacity: 0.9;
+  transition: opacity var(--duration-fast) var(--ease-in-out);
+}
+
+.chat-tts-toggle:hover { opacity: 1; }
+.chat-tts-toggle.off { opacity: 0.35; }
+
 /* ─── Messages Area ─── */
 
 .chat-messages {

pos/static/css/chat.min.css

@@ -104,6 +104,27 @@
 
 .chat-header-close:hover { opacity: 1; }
 
+.chat-header-actions {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+}
+
+.chat-tts-toggle {
+  background: none;
+  border: none;
+  color: #fff;
+  font-size: 1rem;
+  cursor: pointer;
+  padding: var(--space-1);
+  line-height: 1;
+  opacity: 0.9;
+  transition: opacity var(--duration-fast) var(--ease-in-out);
+}
+
+.chat-tts-toggle:hover { opacity: 1; }
+.chat-tts-toggle.off { opacity: 0.35; }
+
 /* ─── Messages Area ─── */
 
 .chat-messages {

pos/static/js/chat.js

@@ -9,8 +9,11 @@
   let isSending = false;
   let isListening = false;
   let recognition = null;
+  let ttsEnabled = true;
+  let ttsUtterance = null;
   const history = [];  // conversation history for AI context
   const hasSpeechAPI = ('webkitSpeechRecognition' in window || 'SpeechRecognition' in window);
+  const hasTTS = ('speechSynthesis' in window);
 
   // ─── Build DOM ───
   function init() {
@@ -71,6 +74,16 @@
       document.getElementById('chatMic').addEventListener('click', toggleVoice);
     }
 
+    // TTS toggle
+    if (hasTTS) {
+      document.getElementById('chatTtsToggle').addEventListener('click', toggleTTS);
+    }
+
+    // Stop TTS when closing
+    document.getElementById('chatClose').addEventListener('click', function () {
+      if (hasTTS) stopSpeaking();
+    });
+
     // Auto-resize textarea
     document.getElementById('chatInput').addEventListener('input', function () {
       this.style.height = 'auto';
@@ -170,6 +183,34 @@
     }, 2000);
   }
 
+  // ─── TTS (Text-to-Speech) ───
+  function toggleTTS() {
+    ttsEnabled = !ttsEnabled;
+    const btn = document.getElementById('chatTtsToggle');
+    if (btn) {
+      btn.classList.toggle('off', !ttsEnabled);
+      btn.setAttribute('title', ttsEnabled ? 'Desactivar lectura de respuestas' : 'Activar lectura de respuestas');
+    }
+    if (!ttsEnabled) stopSpeaking();
+  }
+
+  function speak(text) {
+    if (!hasTTS || !ttsEnabled || !text) return;
+    stopSpeaking();
+    ttsUtterance = new SpeechSynthesisUtterance(text);
+    ttsUtterance.lang = 'es-MX';
+    ttsUtterance.rate = 1.1;
+    ttsUtterance.pitch = 1;
+    window.speechSynthesis.speak(ttsUtterance);
+  }
+
+  function stopSpeaking() {
+    if (hasTTS && window.speechSynthesis.speaking) {
+      window.speechSynthesis.cancel();
+    }
+    ttsUtterance = null;
+  }
+
   // ─── Image Upload (Part identification placeholder) ───
   function handleImageUpload(e) {
     const file = e.target.files && e.target.files[0];
@@ -314,6 +355,7 @@
       const aiMsg = data.response || 'Sin respuesta.';
       addBubble(aiMsg, 'ai');
       history.push({ role: 'assistant', content: aiMsg });
+      speak(aiMsg);
 
       // Vehicle info
       if (data.vehicle && data.vehicle.brand_id) {

pos/templates/accounting.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Contabilidad — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -495,5 +496,6 @@
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/config.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Configuración — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -688,5 +689,6 @@
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/customers.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Nexus Autoparts — Clientes</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -623,5 +624,6 @@
   <script src="/pos/static/js/offline-banner.js" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/dashboard.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Nexus Autoparts — Dashboard</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -460,5 +461,6 @@
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/diagrams.html

@@ -5,11 +5,11 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Diagramas — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
   <link rel="stylesheet" href="/pos/static/css/pos-glass.css" />
-  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/onboarding.css" />
   <link rel="manifest" href="/pos/static/pwa/manifest.json" />
   <meta name="theme-color" content="#F5A623" />
@@ -154,5 +154,6 @@
   <script src="/pos/static/js/sidebar.js" defer></script>
   <script src="/pos/static/js/diagrams.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/fleet.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Flotillas — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -308,5 +309,6 @@
 <script src="/pos/static/js/offline-banner.js" defer></script>
 <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/inventory.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Inventario — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -818,5 +819,6 @@
   <script src="/pos/static/js/offline-banner.js" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/invoicing.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Facturación CFDI — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -1057,5 +1058,6 @@
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/marketplace.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Marketplace B2B — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -512,5 +513,6 @@
     }
   })();
   </script>
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/quotations.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Cotizaciones — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -147,5 +148,6 @@
     loadQuotes();
   })();
   </script>
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/reports.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>Reportes — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -323,5 +324,6 @@
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>

pos/templates/whatsapp.html

@@ -5,6 +5,7 @@
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>WhatsApp — Nexus Autoparts POS</title>
+  <link rel="stylesheet" href="/pos/static/css/chat.css" />
   <link rel="stylesheet" href="/pos/static/css/tokens.css" />
   <link rel="stylesheet" href="/pos/static/css/common.css" />
   <link rel="stylesheet" href="/pos/static/css/sidebar.css" />
@@ -130,5 +131,6 @@ function posLogout(){localStorage.removeItem('pos_token');window.location.href='
 <script src="/pos/static/js/pos-utils.js" defer></script>
   <script src="/pos/static/js/sidebar.js" defer></script>
 
+  <script src="/pos/static/js/chat.js" defer></script>
 </body>
 </html>