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/tapable/lib/MultiHook.js

@@ -0,0 +1,54 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+"use strict";
+
+const Hook = require("./Hook");
+
+class MultiHook {
+	constructor(hooks, name = undefined) {
+		this.hooks = hooks;
+		this.name = name;
+	}
+
+	tap(options, fn) {
+		for (const hook of this.hooks) {
+			hook.tap(options, fn);
+		}
+	}
+
+	tapAsync(options, fn) {
+		for (const hook of this.hooks) {
+			hook.tapAsync(options, fn);
+		}
+	}
+
+	tapPromise(options, fn) {
+		for (const hook of this.hooks) {
+			hook.tapPromise(options, fn);
+		}
+	}
+
+	isUsed() {
+		for (const hook of this.hooks) {
+			if (hook.isUsed()) return true;
+		}
+		return false;
+	}
+
+	intercept(interceptor) {
+		for (const hook of this.hooks) {
+			hook.intercept(interceptor);
+		}
+	}
+
+	withOptions(options) {
+		return new MultiHook(
+			this.hooks.map((h) => h.withOptions(options)),
+			this.name
+		);
+	}
+}
+
+module.exports = MultiHook;