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/object.fromentries/implementation.js

@@ -0,0 +1,18 @@
+'use strict';
+
+var AddEntriesFromIterable = require('es-abstract/2024/AddEntriesFromIterable');
+var CreateDataPropertyOrThrow = require('es-abstract/2024/CreateDataPropertyOrThrow');
+var RequireObjectCoercible = require('es-object-atoms/RequireObjectCoercible');
+var ToPropertyKey = require('es-abstract/2024/ToPropertyKey');
+
+var adder = function addDataProperty(key, value) {
+	var O = this; // eslint-disable-line no-invalid-this
+	var propertyKey = ToPropertyKey(key);
+	CreateDataPropertyOrThrow(O, propertyKey, value);
+};
+
+module.exports = function fromEntries(iterable) {
+	RequireObjectCoercible(iterable);
+
+	return AddEntriesFromIterable({}, iterable, adder);
+};