The server now actually runs fully, it saves worlds to any S3-like server and allows downloading and uploading custom ones. It autosaves the worlds once every 5 minutes and when the server is shut down, and restarts the servers when the configuration is changed. It does not yet allow you to add operators to the server.
Added server configuration UI autogeneration.
It automatically shows only the configuration options supported by the server, requiring me to only implement the backend handler and add the option to the list of field names.
Got basic functionality, with primitive web ui and nearly complete backend. The code is too messy to use, and I will soon rewrite most of it.