J-PCMCI+ multivariate space-dummy pin

Suite path: conformance/discovery/jpcmci_plus_two_env_space_dummy_mv

Exercises SpaceDummyCiMode::MultivariateBlock with include_space_dummy=true on ≥3 environments (so ≥2 one-hot space columns collapse to one logical node).

Library-only expected (no external multivariate space-dummy oracle required).

Expected summary

Top-level keys: algorithm_id, include_space_dummy, max_logical_space_dummy_ids, min_envs, min_links, min_nodes, notes, require_multivariate_diagnostic, space_dummy_ci, tolerance_class (10 fields).