Build XCUI splitter foundation and test harness

tests/UI/Editor/integration/shared/src/EditorValidationScenario.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <filesystem>
+#include <string>
+#include <string_view>
+
+namespace XCEngine::Tests::EditorUI {
+
+enum class UIValidationDomain : unsigned char {
+    Editor = 0,
+    Runtime
+};
+
+struct EditorValidationScenario {
+    std::string id = {};
+    UIValidationDomain domain = UIValidationDomain::Editor;
+    std::string categoryId = {};
+    std::string displayName = {};
+    std::filesystem::path documentPath = {};
+    std::filesystem::path themePath = {};
+    std::filesystem::path captureRootPath = {};
+};
+
+const EditorValidationScenario& GetDefaultEditorValidationScenario();
+const EditorValidationScenario* FindEditorValidationScenario(std::string_view id);
+
+} // namespace XCEngine::Tests::EditorUI