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/UnhandledSchemeError.js

@@ -0,0 +1,33 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Ivan Kopeykin @vankop
+*/
+
+"use strict";
+
+const WebpackError = require("./WebpackError");
+const makeSerializable = require("./util/makeSerializable");
+
+class UnhandledSchemeError extends WebpackError {
+	/**
+	 * @param {string} scheme scheme
+	 * @param {string} resource resource
+	 */
+	constructor(scheme, resource) {
+		super(
+			`Reading from "${resource}" is not handled by plugins (Unhandled scheme).` +
+				'\nWebpack supports "data:" and "file:" URIs by default.' +
+				`\nYou may need an additional plugin to handle "${scheme}:" URIs.`
+		);
+		this.file = resource;
+		this.name = "UnhandledSchemeError";
+	}
+}
+
+makeSerializable(
+	UnhandledSchemeError,
+	"webpack/lib/UnhandledSchemeError",
+	"UnhandledSchemeError"
+);
+
+module.exports = UnhandledSchemeError;