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/objectWithoutProperties.js

@@ -0,0 +1,13 @@
+import objectWithoutPropertiesLoose from "./objectWithoutPropertiesLoose.js";
+function _objectWithoutProperties(e, t) {
+  if (null == e) return {};
+  var o,
+    r,
+    i = objectWithoutPropertiesLoose(e, t);
+  if (Object.getOwnPropertySymbols) {
+    var n = Object.getOwnPropertySymbols(e);
+    for (r = 0; r < n.length; r++) o = n[r], -1 === t.indexOf(o) && {}.propertyIsEnumerable.call(e, o) && (i[o] = e[o]);
+  }
+  return i;
+}
+export { _objectWithoutProperties as default };