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/lodash/_cloneArrayBuffer.js

@@ -0,0 +1,16 @@
+var Uint8Array = require('./_Uint8Array');
+
+/**
+ * Creates a clone of `arrayBuffer`.
+ *
+ * @private
+ * @param {ArrayBuffer} arrayBuffer The array buffer to clone.
+ * @returns {ArrayBuffer} Returns the cloned array buffer.
+ */
+function cloneArrayBuffer(arrayBuffer) {
+  var result = new arrayBuffer.constructor(arrayBuffer.byteLength);
+  new Uint8Array(result).set(new Uint8Array(arrayBuffer));
+  return result;
+}
+
+module.exports = cloneArrayBuffer;