feature: version one notification feature implemented.

backend/package.json

@@ -41,8 +41,10 @@
     "@nestjs/jwt": "^11.0.2",
     "@nestjs/passport": "^11.0.5",
     "@nestjs/platform-express": "^11.0.1",
+    "@nestjs/platform-socket.io": "^11.1.28",
     "@nestjs/swagger": "^11.2.6",
     "@nestjs/throttler": "^6.5.0",
+    "@nestjs/websockets": "^11.1.28",
     "@prisma/client": "^6.19.2",
     "adminjs": "^7.8.17",
     "axios": "^1.13.5",
@@ -64,6 +66,7 @@
     "prisma": "^6.19.2",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1",
+    "socket.io": "^4.8.3",
     "styled-components": "^6.3.11",
     "swagger-ui-express": "^5.0.1"
   },