codegen will run inside an infinite loop when watching the file it outputs

If you run the codegen and include the output file in the queries, then watch will run an infinite loop. Maybe we could ignore the output file in the files we watch?

Run codegen in watch mode with the generated output included in the queries to reproduce the repeated triggering. Locate the watch and file-filtering entry points, then verify that changes to the generated output no longer restart watch indefinitely; done means normal source changes still trigger codegen.

Written by the indexing model from the issue text.