Initial commit: Developer Tools MVP with visual editor

- Complete React app with 7 developer tools
- JSON Tool with visual structured editor
- Serialize Tool with visual structured editor
- URL, Base64, CSV/JSON, Beautifier, Diff tools
- Responsive navigation with dropdown menu
- Dark/light mode toggle
- Mobile-responsive design with sticky header
- All tools working with copy/paste functionality

node_modules/@babel/runtime/helpers/esm/isNativeReflectConstruct.js

@@ -0,0 +1,9 @@
+function _isNativeReflectConstruct() {
+  try {
+    var t = !Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {}));
+  } catch (t) {}
+  return (_isNativeReflectConstruct = function _isNativeReflectConstruct() {
+    return !!t;
+  })();
+}
+export { _isNativeReflectConstruct as default };