Replace polling with websocket live sync

package.json

@@ -22,6 +22,7 @@
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
     "@types/supertest": "^7.2.0",
+    "@types/ws": "^8.18.1",
     "@vitejs/plugin-react": "^6.0.1",
     "concurrently": "^9.2.1",
     "esbuild": "^0.27.4",
@@ -35,6 +36,7 @@
   "dependencies": {
     "express": "^5.2.1",
     "react": "^19.2.4",
-    "react-dom": "^19.2.4"
+    "react-dom": "^19.2.4",
+    "ws": "^8.20.0"
   }
 }