refactor: split server and app for clean testing and CI/CD compatibility

Author: vikashkrdeveloper

package.json

@@ -5,7 +5,7 @@
   "main": "server.js",
   "scripts": {
     "start": "node server.js",
-    "test": "jest"
+    "test": "jest --detectOpenHandles"
   },
   "dependencies": {
     "express": "^4.18.2"
@@ -14,4 +14,4 @@
     "jest": "^29.5.0",
     "supertest": "^6.3.3"
   }
-}
+}