Implements getEuclideanCircleFromHyperbolic() in C++ (hyperboloid model
→ Poincaré disk via Lorentz boost + circumcircle). Ports the 2 Java tests
that were the only remaining candidates not requiring HDS or a solver.
All other unported tests (DataTypesTest, SchottkyIOTest,
UniformizationDataTest, BranchedCoverTorusTest) are blocked by XML
serialization or HDS – stubs remain for Phase 4.
Test totals: 36 registered | 23 passed | 13 skipped | 0 failed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
