[LunaStev]

The representative Release job serializes core integration tests, properties, a second full-library interchange build, and Criterion dependency compilation. Move extended validation into a parallel job, build all three extended components in one Cabal plan, and keep their flags/build directory consistent so the library is compiled once. The interchange helper accepts repeatable Cabal flags to preserve that plan.

All existing core compiler/build-type checks, portability probes, full optional differential checks, fuzzing and benchmark fixture checks remain. Reuse the previous Release cache on the first extended run, then save an extended-validation cache.

Validation: actionlint, Ruff and whitespace checks pass. Build the three components together locally, then run properties, Criterion fixtures and 577 core interchange checks from that build; all pass with no additional module compilation. Local Arrow/HDF5/ONNX dependencies are absent; CI retains --require-optional with all dependencies installed.