feat: add WebSocket real-time crowd data simulation

websocket-server.js

@@ -0,0 +1,38 @@
+/**
+ * WebSocket server for real-time crowd density simulation
+ * Pushes mock data every 2 seconds to connected clients
+ */
+const WebSocket = require('ws');
+
+const wss = new WebSocket.Server({ port: 8080 });
+
+function generateCrowdData() {
+  const zones = [
+    { id: 'zone-a', name: 'Main Entrance',  density: Math.floor(Math.random() * 100) },
+    { id: 'zone-b', name: 'Hall B',         density: Math.floor(Math.random() * 100) },
+    { id: 'zone-c', name: 'Food Court',     density: Math.floor(Math.random() * 100) },
+    { id: 'zone-d', name: 'Emergency Exit', density: Math.floor(Math.random() * 20)  },
+  ].map(z => ({
+    ...z,
+    status: z.density > 80 ? 'critical' : z.density > 60 ? 'warning' : 'normal',
+  }));
+
+  return { timestamp: new Date().toISOString(), zones };
+}
+
+wss.on('connection', (ws) => {
+  console.log('Client connected');
+  const interval = setInterval(() => {
+    if (ws.readyState === WebSocket.OPEN) {
+      ws.send(JSON.stringify(generateCrowdData()));
+    }
+  }, 2000);
+
+  ws.on('close', () => {
+    clearInterval(interval);
+    console.log('Client disconnected');
+  });
+});
+
+console.log('WebSocket server running on ws://localhost:8080');
+module.exports = wss;