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/construct.js

@@ -0,0 +1,10 @@
+import isNativeReflectConstruct from "./isNativeReflectConstruct.js";
+import setPrototypeOf from "./setPrototypeOf.js";
+function _construct(t, e, r) {
+  if (isNativeReflectConstruct()) return Reflect.construct.apply(null, arguments);
+  var o = [null];
+  o.push.apply(o, e);
+  var p = new (t.bind.apply(t, o))();
+  return r && setPrototypeOf(p, r.prototype), p;
+}
+export { _construct as default };