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/es-iterator-helpers/Iterator/implementation.js

@@ -0,0 +1,29 @@
+'use strict';
+
+var GetIntrinsic = require('get-intrinsic');
+var hasPropertyDescriptors = require('has-property-descriptors')();
+
+var $TypeError = require('es-errors/type');
+var $defineProperty = hasPropertyDescriptors && GetIntrinsic('%Object.defineProperty%', true);
+
+var iterProto = require('iterator.prototype');
+var callBound = require('call-bound');
+
+var $isPrototypeOf = callBound('Object.prototype.isPrototypeOf');
+
+var $Iterator = typeof Iterator === 'function' ? Iterator : function Iterator() {
+	if (
+		!(this instanceof Iterator)
+		|| this.constructor === Iterator
+		|| !$isPrototypeOf(Iterator, this.constructor)
+	) {
+		throw new $TypeError('`Iterator` can not be called or constructed directly');
+	}
+};
+
+if ($Iterator.prototype !== iterProto) {
+	$Iterator.prototype = iterProto;
+}
+$defineProperty($Iterator, 'prototype', { writable: false });
+
+module.exports = $Iterator;