feat: update build output directory to 'dist' in package.json and set outputDirectory in vercel.json

vercel.json

@@ -1,5 +1,6 @@
 {
 	"$schema": "https://openapi.vercel.sh/vercel.json",
 	"bunVersion": "1",
+	"outputDirectory": "dist",
 	"rewrites": [{ "source": "/(.*)", "destination": "/api/relay" }]
 }