feat: GLTF/GLB export with normals + B-Rep tessellation + pipeline example

include/vde/foundation/io_gltf.h

@@ -1,11 +1,31 @@
 #pragma once
 #include "vde/mesh/halfedge_mesh.h"
+#include "vde/brep/brep.h"
 #include <string>
+#include <vector>
+#include <optional>
 
 namespace vde::foundation {
 
-/// Export mesh to glTF 2.0 (JSON + optional embedded binary)
+/// GLTF export options
+struct GltfOptions {
+    bool binary = true;              // GLB (single file) vs glTF (JSON + .bin)
+    bool include_normals = true;     // Compute and export vertex normals
+    bool include_colors = false;     // Per-vertex colors
+    std::vector<float> vertex_colors; // RGB per vertex (if include_colors)
+};
+
+/// Export mesh to glTF 2.0 / GLB
 /// Returns true on success
-bool write_gltf(const std::string& filepath, const mesh::HalfedgeMesh& mesh);
+bool write_gltf(const std::string& filepath, const mesh::HalfedgeMesh& mesh,
+                const GltfOptions& options = GltfOptions{});
+
+/// Export B-Rep model to GLB by tessellating faces
+/// @param filepath Output file (.glb recommended)
+/// @param model B-Rep model to export
+/// @param tessellation_res Resolution for curved surfaces (segments per edge)
+/// @return true on success
+bool write_brep_gltf(const std::string& filepath, const brep::BrepModel& model,
+                     int tessellation_res = 32);
 
 }  // namespace vde::foundation