feat: Add real-time visitor map with IP geolocation

- Add latitude/longitude columns to visitor_logs model
- Update visitor_service to fetch and store coordinates from ip-api.com
- Add /admin/map-data API endpoint for map visualization
- Create VisitorMap component using Leaflet/OpenStreetMap
- Integrate map into visitor-stats admin page
- 30-second auto-refresh with animation for new visitors
- Color-coded markers (red: active, blue: recent)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/package.json

@@ -14,12 +14,15 @@
     "@heroicons/react": "^2.1.1",
     "@stripe/react-stripe-js": "^5.4.1",
     "@stripe/stripe-js": "^8.6.0",
+    "@types/leaflet": "^1.9.21",
     "axios": "^1.6.5",
     "framer-motion": "^12.23.25",
+    "leaflet": "^1.9.4",
     "next": "14.1.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
     "react-hook-form": "^7.49.3",
+    "react-leaflet": "^4.2.1",
     "zustand": "^4.5.0"
   },
   "devDependencies": {