feat(euler-beam-3d): add global transform recovery

src/fesa/elements/euler_beam_3d.hpp

@@ -6,6 +6,7 @@ namespace fesa::elements {
 
 using Vector12 = std::array<double, 12>;
 using Matrix12 = std::array<double, 144>;
+using Vector3 = std::array<double, 3>;
 
 struct EulerBeam3DSection {
     double young_modulus;
@@ -16,10 +17,23 @@ struct EulerBeam3DSection {
     double second_moment_z;
 };
 
+struct EulerBeam3DGeometry {
+    Vector3 node1;
+    Vector3 node2;
+    Vector3 orientation;
+};
+
 Matrix12 euler_beam_3d_local_stiffness(double length, const EulerBeam3DSection& section);
 
 Vector12 euler_beam_3d_local_end_forces(double length,
                                         const EulerBeam3DSection& section,
                                         const Vector12& local_displacements);
 
+Matrix12 euler_beam_3d_global_stiffness(const EulerBeam3DGeometry& geometry,
+                                        const EulerBeam3DSection& section);
+
+Vector12 euler_beam_3d_global_end_forces(const EulerBeam3DGeometry& geometry,
+                                         const EulerBeam3DSection& section,
+                                         const Vector12& global_displacements);
+
 } // namespace fesa::elements