Polish explorer frontend validation and utility pages

frontend/package.json

@@ -4,9 +4,10 @@
   "private": true,
   "packageManager": "pnpm@10.0.0",
   "scripts": {
-    "dev": "next dev",
+    "dev": "sh -c 'HOST=${HOST:-127.0.0.1}; PORT=${PORT:-3000}; next dev -H \"$HOST\" -p \"$PORT\"'",
     "build": "next build",
     "build:check": "npm run lint && npm run type-check && npm run build",
+    "smoke:routes": "node ./scripts/smoke-routes.mjs",
     "start": "PORT=${PORT:-3000} node .next/standalone/server.js",
     "start:next": "next start",
     "lint": "next lint",