Add vue-router, login/setup flow and backend logging

Refactor frontend to route-based navigation with vue-router, add
system setup and login pages with API integration. Add structured
logging, access-log middleware and startup lifecycle to FastAPI
backend.

web/package.json

@@ -14,10 +14,12 @@
     "@vitejs/plugin-vue": "^5.2.4",
     "@vueuse/motion": "^3.0.3",
     "chart.js": "^4.5.1",
+    "pg": "^8.13.1",
     "primeicons": "^7.0.0",
     "primevue": "^4.5.5",
     "vite": "^5.4.19",
     "vue": "^3.5.13",
-    "vue-chartjs": "^5.3.3"
+    "vue-chartjs": "^5.3.3",
+    "vue-router": "^4.5.1"
   }
 }