feat(cpp-object-oriented-modular-refactoring): step 14 - runtime-element-factory

include/fesa/elements/mitc4_shell.h

@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "fesa/core/status.h"
+#include "fesa/elements/element.h"
 #include "fesa/elements/element_definition.h"
 #include "fesa/materials/isotropic_linear_elastic_material.h"
 #include "fesa/math/matrix.h"
@@ -114,7 +115,7 @@ struct Mitc4PhysicalRecovery {
 
 /// @brief Implements the approved small-rotation FESA-MITC4 shell kernel.
 /// @note Physical and numerical drilling contributions remain separate.
-class Mitc4Shell {
+class Mitc4Shell final : public Element {
  public:
   /// @brief Creates a validated shell kernel from four non-owning node
   /// pointers.
@@ -128,6 +129,16 @@ class Mitc4Shell {
       std::array<std::array<double, 3>, 4> initial_directors,
       const ShellSection& section, const LinearElasticMaterial& material);
 
+  /// @brief Returns the factory-bound MITC4 DOF order.
+  const ElementDofLayout& DofLayout() const noexcept override;
+
+  /// @brief Computes stabilized MITC4 stiffness through the runtime contract.
+  Result<ElementStiffnessContribution> ComputeStiffness() const override;
+
+  /// @brief Recovers physical MITC4 rows through the runtime contract.
+  Result<ElementResultBundle> Recover(
+      const Vector& element_displacement) const override;
+
   /// @brief Evaluates bilinear shape functions and derivatives.
   static Mitc4ShapeFunctions ShapeFunctions(double xi, double eta) noexcept;
 
@@ -183,6 +194,12 @@ class Mitc4Shell {
       const Vector& global_element_displacement24) const;
 
  private:
+  friend class ElementFactory;
+
+  /// @brief Binds Domain identity after the numerical candidate is valid.
+  void BindRuntime(ElementDofLayout layout, EntityIndex element_index,
+                   SourceLocation location);
+
   /// @brief Stores covariant, reciprocal, frame, and Jacobian data at one
   /// point.
   struct GeometryData {
@@ -221,6 +238,9 @@ class Mitc4Shell {
   double poisson_ratio_;
   SourceLocation source_location_;
   std::string identity_;
+  ElementDofLayout dof_layout_;
+  EntityIndex element_index_{0U};
+  SourceLocation runtime_location_;
 };
 
 }  // namespace fesa