new calculation approach with unique sessions, new API endpoint to get list of active sessions, fix for UNDEF user, UI and Back to support certificate management still under development

UI/client/package.json

@@ -10,9 +10,11 @@
   },
   "dependencies": {
     "@fortawesome/fontawesome-free": "^7.1.0",
+    "axios": "^1.13.2",
     "bootstrap": "^5.3.8",
     "chart.js": "^4.5.1",
     "sass": "^1.97.2",
+    "sweetalert2": "^11.26.17",
     "vue": "^3.5.24",
     "vue-router": "^4.6.4"
   },