Scaffold iniziale Vue 3 + Vite

Aggiunge struttura base del progetto: package.json, vite.config.js,
index.html con viewport mobile, main.js, CSS globale mobile-first
e .gitignore.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -0,0 +1,17 @@
+{
+  "name": "biteplan",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "vue": "^3.4.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-vue": "^5.0.0",
+    "vite": "^5.0.0"
+  }
+}