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/core-js/full/instance/clamp.js

@@ -0,0 +1,14 @@
+'use strict';
+var isPrototypeOf = require('../../internals/object-is-prototype-of');
+var numberMethod = require('../number/virtual/clamp');
+
+var NumberPrototype = String.prototype;
+
+module.exports = function (it) {
+  var ownProperty = it.clamp;
+  // eslint-disable-next-line es/no-nonstandard-string-prototype-properties -- safe
+  if (typeof it == 'number' || it === NumberPrototype || (isPrototypeOf(NumberPrototype, it) && ownProperty === NumberPrototype.clamp)) {
+    return numberMethod;
+  }
+  return ownProperty;
+};