OpenVdra/SmartSpawner ? reverse-engineered prompt

Build me a Minecraft server plugin called SmartSpawner for Paper and Folia that lets players use a special spawner block or menu to generate items and experience instead of spawning mobs.

I want it to feel like a polished GUI based system where admins or players with permission can open a menu, choose what gets produced, set rates or costs, and manage the spawner easily in game. It should work on Minecraft 1.21.6 and up, and be compatible with Java 25.

Please include sensible config files, permissions, and messages, plus support for multiple languages if that fits naturally. Make sure it’s clean, performant, and safe for modern Paper and Folia servers. If there are any details that depend on current APIs or server behavior, look up the latest docs online and use the right approach.