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/config.py

@@ -43,6 +43,15 @@ if not OPENROUTER_API_KEY:
         RuntimeWarning
     )
 
+# ─── Hermes Agent ──────────────────────────────────────────────────────────
+HERMES_API_URL = os.environ.get("HERMES_API_URL", "http://192.168.10.71:8642/v1")
+HERMES_API_KEY = os.environ.get("HERMES_API_KEY")
+if not HERMES_API_KEY:
+    warnings.warn(
+        "HERMES_API_KEY not set. Hermes Agent integration will fall back to OpenRouter.",
+        RuntimeWarning
+    )
+
 # ─── SMTP ──────────────────────────────────────────────────────────────────
 SMTP_HOST = os.environ.get('SMTP_HOST', 'smtp.gmail.com')
 SMTP_PORT = int(os.environ.get('SMTP_PORT', '587'))
@@ -75,3 +84,12 @@ MEILI_ENABLED = os.environ.get('MEILI_ENABLED', 'true').lower() == 'true'
 
 # ─── Catalog OEM Access ────────────────────────────────────────────────────
 CATALOG_OEM_ENABLED = os.environ.get('CATALOG_OEM_ENABLED', 'false').lower() == 'true'
+
+# ─── QWEN AI Fitment (private cloud server) ────────────────────────────────
+QWEN_API_URL = os.environ.get('QWEN_API_URL', '')
+QWEN_API_KEY = os.environ.get('QWEN_API_KEY', '')
+QWEN_MODEL = os.environ.get('QWEN_MODEL', 'qwen3.6')
+
+
+# ─── Internal Cron / Job Security ──────────────────────────────────────────
+INTERNAL_API_KEY = os.environ.get('INTERNAL_API_KEY', '')