deps/CMakeLists.txt only extracted CGAL when WITH_CGAL=ON.
With -DWITH_CGAL_TESTS=ON the CGAL include path was never populated,
causing fatal error: CGAL/Simple_cartesian.h: No such file or directory.
Fix: extract CGAL-6.1.1 for both WITH_CGAL and WITH_CGAL_TESTS.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
macOS filesystem is case-insensitive so both spellings worked locally,
but the Linux container (CI) could not find the file and failed with
"does not contain a CMakeLists.txt file".
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>