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/errors/BuildCycleError.js

@@ -0,0 +1,27 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const WebpackError = require("../WebpackError");
+
+/** @typedef {import("../Module")} Module */
+
+class BuildCycleError extends WebpackError {
+	/**
+	 * Creates an instance of ModuleDependencyError.
+	 * @param {Module} module the module starting the cycle
+	 */
+	constructor(module) {
+		super(
+			"There is a circular build dependency, which makes it impossible to create this module"
+		);
+
+		this.name = "BuildCycleError";
+		this.module = module;
+	}
+}
+
+module.exports = BuildCycleError;