Enable network access for Vite dev server

Add --host flag to dev and preview scripts so the frontend
is accessible from other machines on the network (useful for
remote development on Pi)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/package.json

@@ -4,10 +4,10 @@
   "version": "0.0.0",
   "type": "module",
   "scripts": {
-    "dev": "vite",
+    "dev": "vite --host",
     "build": "tsc -b && vite build",
     "lint": "eslint .",
-    "preview": "vite preview"
+    "preview": "vite preview --host"
   },
   "dependencies": {
     "@radix-ui/react-accordion": "^1.2.12",