Produces the single self-contained fat jar that the Python wheel mounts
via --jars, for Spark 3.5.x / Scala 2.13.
WHY THIS MODULE EXISTS
----------------------
The pytest plugin mounts exactly ONE jar and sets
spark.sql.extensions=io.github.wpunit13.mutator.MutatorSparkExtension
Therefore that one jar must contain everything the driver needs:
mutator-core (MutantRegistry, hashing, catalog, reports and
SessionResetFacade, all ...