Is there any plan in place to create an API for the web UI, or any other type of API wrapper for the validator?

My primary motivation is in being able to build the service into an automated pipeline; export gtfs -> POST to a running instance of the validator -> Receive results.json

I can see an argument for building it into the existing code, since there is already a Springboot web application, but the API also would not necessarily need the UI aspect, and could also be built as a separate module, something like gtfs-validator-service