Code generation doesn't delete unused files

Because codegen puts things in their own `__generated__` folder adjacent to the file containing the queries, if you move a query, the old file remains and clutters up IDE autocomplete. This inhibits the refactoring process.

I believe developer experience would be improved if the old file were deleted or if all the types were placed in a global types file.

Start by tracing the code generation path that writes files into the adjacent __generated__ folder. Determine how moved queries are detected and whether stale outputs can be identified safely; the issue leaves deletion versus a global types file as an unresolved design choice. Done means the chosen approach prevents obsolete generated files from cluttering IDE autocomplete.

Written by the indexing model from the issue text.