chore: upgrade vite to 8 and plugin-vue to 6

Resolves the high-severity esbuild advisory (GHSA-gv7w-rqvm-qjhr).
vite 6/7 still pin vulnerable esbuild; vite 8.0.16 ships the patched
0.28.x. npm audit now reports 0 vulnerabilities and the build passes.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -6,13 +6,15 @@
   "scripts": {
     "dev": "vite --host",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "worker:dev": "npx wrangler dev --config worker/wrangler.toml",
+    "worker:deploy": "npx wrangler deploy --config worker/wrangler.toml"
   },
   "dependencies": {
     "vue": "3.5.13"
   },
   "devDependencies": {
-    "@vitejs/plugin-vue": "5.2.1",
-    "vite": "6.4.2"
+    "@vitejs/plugin-vue": "6.0.7",
+    "vite": "8.0.16"
   }
 }