feat: add "Add component" button

tests/destrum_tests.cpp

@@ -13,6 +13,8 @@
 #include <destrum/ObjectModel/GameObject.h>
 #include <destrum/Scene/Scene.h>
 #include <destrum/Scene/SceneManager.h>
+#include <destrum/Serialization/ComponentFactory.h>
+#include <destrum/Serialization/ComponentRegistry.h>
 #include <destrum/Serialization/SceneSerializer.h>
 #include <destrum/Physics/SimplePhysicsWorld.h>
 #include <destrum/Physics/JoltPhysicsWorld.h>
@@ -161,6 +163,32 @@ namespace {
         SceneManager::GetInstance().Destroy();
     }
 
+    void testEngineComponentRegistration()
+    {
+        RegisterEngineComponents();
+
+        const char* canonicalNames[] = {
+            "MeshRendererComponent",
+            "Rotator",
+            "Spinner",
+            "OrbitAndSpin",
+            "Animator",
+            "Rigidbody",
+            "BoxCollider",
+            "SphereCollider",
+            "CapsuleCollider"
+        };
+        for (const char* name : canonicalNames) {
+            check(ComponentFactory::IsRegistered(name),
+                  "all canonical engine component names must be registered");
+        }
+
+        check(!ComponentFactory::IsRegistered("MeshRenderer"),
+              "MeshRenderer legacy alias must not be registered");
+        check(!ComponentFactory::IsRegistered("RigidBody"),
+              "RigidBody legacy alias must not be registered");
+    }
+
     void testAssetPathValidation()
     {
         const auto root = std::filesystem::temp_directory_path() / "destrum_asset_test";
@@ -440,6 +468,7 @@ int main()
     testEventMutation();
     testEventRemoval();
     testComponentRemoval();
+    testEngineComponentRegistration();
     testAssetPathValidation();
     testLegacySceneLoad();
     testSceneLoadRollback();