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/webpack/lib/HotUpdateChunk.js

@@ -0,0 +1,19 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const Chunk = require("./Chunk");
+
+/** @typedef {import("./ChunkGraph")} ChunkGraph */
+/** @typedef {import("./util/Hash")} Hash */
+
+class HotUpdateChunk extends Chunk {
+	constructor() {
+		super();
+	}
+}
+
+module.exports = HotUpdateChunk;