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/peers.json

@@ -0,0 +1,19 @@
+{
+  "instance_name": "Refaccionaria Demo",
+  "instance_id": "refac-demo-001",
+  "tenant_id": 11,
+  "peers": [
+    {
+      "name": "Refaccionaria B",
+      "url": "http://192.168.1.20:5001",
+      "enabled": true
+    },
+    {
+      "name": "Refaccionaria C",
+      "url": "http://192.168.1.30:5001",
+      "enabled": true
+    }
+  ],
+  "peer_timeout_seconds": 3,
+  "notes": "Edit the 'peers' list with the actual IPs of the other instances on your network. Each instance has its own copy of this file with different peers."
+}