By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Mutation: seed the global RNG in the spec-forest runners The global System.Random generator was only seeded by the top-level sydTest runner. The mutation and coverage children run a forest directly via runSpecForestSynchronously, bypassing that seeding, so tests drawing from the global generator (randomIO, newStdGen, ...) rather than QuickCheck's replay seed were non-reproducible under those children — a source of spurious mutation kills or survivors. Move setPseudorandomness down into Test.Syd.Run and call it from all four forest runners, so every entry point that runs a forest seeds the global generator and no future entry point can bypass it. Add a regression test, bump sydtest to 0.27.1.0, and add a changelog entry.