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/src/app/admin/visitor-stats/page.tsx

@@ -1,8 +1,22 @@
 'use client';
 
 import { useState, useEffect } from 'react';
+import dynamic from 'next/dynamic';
 import { visitorApi, VisitorStatsOverview, TopPage, TopReferrer, ChartData, RealtimeStats } from '@/lib/api';
 
+// Dynamic import for VisitorMap (no SSR - Leaflet requires browser)
+const VisitorMap = dynamic(() => import('@/components/VisitorMap'), {
+  ssr: false,
+  loading: () => (
+    <div className="bg-white rounded-lg shadow p-6">
+      <div className="animate-pulse">
+        <div className="h-6 bg-gray-200 rounded w-48 mb-4"></div>
+        <div className="h-96 bg-gray-200 rounded"></div>
+      </div>
+    </div>
+  ),
+});
+
 // Country code to name and flag mapping
 const countryInfo: Record<string, { name: string; flag: string }> = {
   MN: { name: 'Mongolia', flag: '🇲🇳' },
@@ -390,6 +404,9 @@ export default function VisitorStatsPage() {
       {/* Country Stats - Full Width */}
       <CountryStatsCard data={overview?.country_breakdown || {}} />
 
+      {/* Real-time Visitor Map */}
+      <VisitorMap refreshInterval={30} />
+
       {/* Device & Browser Breakdowns */}
       <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
         <BreakdownCard