test_exchange_window, test_raw_exchange_gpu (one fine(block) helper for
the repeated circle+jet construction), test_refinement_jets,
test_multiple_pinned_remap_gpu and test_pinned_body_remap_gpu pass
refinements/level_* lists. Dense fine levels stay level_blocks=[None,
None|block] as before. Assertions unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>