By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Revert MutationId [Text] back to [String] to fix transitive linker failure The Text-based approach required injecting mutationTextPack calls into every compiled module, creating unresolved symbol references in static archives. Downstream packages that link against those archives fail unless sydtest-mutation-plugin is in their dependency graph. Keep MutationId [String] (no external symbol references injected) but fix GenValid MutationId to generate via T.unpack <$> genValid, avoiding the surrogate-character roundtrip failures that motivated the Text switch.