Add users and network settings tabs with admin protections.

List and delete accounts with last-admin and Administrators-group guards, and expose editable network settings via the configuration UI.

webui/package.json

@@ -12,6 +12,7 @@
     "test:watch": "vitest"
   },
   "dependencies": {
+    "qrcode": "^1.5.4",
     "react": "^19.2.7",
     "react-dom": "^19.2.7"
   },
@@ -20,6 +21,7 @@
     "@testing-library/react": "^16.3.2",
     "@testing-library/user-event": "^14.6.1",
     "@types/node": "^24.13.2",
+    "@types/qrcode": "^1.5.6",
     "@types/react": "^19.2.17",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "^6.0.3",