Scaffold plant app - MQTT monitoring for boiler-room equipment

Read-only monitoring/alerting for boilers, water softener, calorifiers
and pumps via a generic MQTT-topic-prefix asset model, so new
equipment can be onboarded without new ingestion code. Threshold and
stale-data alert rules with email + in-app notification.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "hnf-plant-frontend",
+  "version": "1.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "lucide-react": "^0.468.0",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-router-dom": "^6.28.0"
+  },
+  "devDependencies": {
+    "@types/react": "^18.3.1",
+    "@types/react-dom": "^18.3.1",
+    "@vitejs/plugin-react": "^4.3.4",
+    "typescript": "^5.7.2",
+    "vite": "^6.0.5"
+  }
+}