refactor(cylinder_face): use geometric hash based on world_to_local transform

Instead of relying on object identity or raw transform parameters, the hasher
now uses intrinsic geometric properties to determine cylinder equivalence.

The hash is computed from:
- G = R^T * R  : encodes the cylinder's cross-sectional metric and axis direction
- v = R * d    : encodes the axial offset in the radial plane

where R is the top-left 2x3 submatrix of the world_to_local linear part,
and d is its translation vector. This ensures that two cylinder faces
with the same shape, orientation, and central axis (even if parameterized
differently) produce the same hash.

primitive_process/interface/subface/simple/cylinder_face.hpp

@@ -34,8 +34,20 @@ template <>
 struct hasher<internal::cylinder_paired_model_matrix> {
     size_t operator()(const internal::cylinder_paired_model_matrix &block) const
     {
-        Eigen::Matrix<double, 2, 4> character_rows = block.data->local_to_world.matrix().topRows<2>();
+        const auto& mat = block.data->local_to_world.matrix(); // 3x4
-        return XXH3_64bits(character_rows.data(), sizeof(decltype(character_rows)));
+        Eigen::Matrix3d A = mat.block<3,3>(0,0);               
+        Eigen::Vector3d b = mat.col(3);
+
+        Eigen::Matrix3d B = A.inverse();
+        Eigen::Matrix<double, 2, 3> R = B.topRows<2>();
+
+        Eigen::Matrix3d G = R.transpose() * R;
+        Eigen::Vector2d zero_proj = R * b;
+
+        size_t h = XXH3_64bits(G.data(), sizeof(Eigen::Matrix3d));
+        h ^= XXH3_64bits(zero_proj.data(), sizeof(Eigen::Vector2d));
+
+        return h;
     }
 };