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/adjust-sourcemap-loader/lib/process/get-error.js

@@ -0,0 +1,17 @@
+'use strict';
+
+var PACKAGE_NAME = require('../../package.json').name;
+
+/**
+ * Get an Error instance for the given message
+ * @param {...*} message Any number of message arguments
+ * @returns {Error}
+ */
+function getError() {
+  var message = (PACKAGE_NAME + ':\n' + Array.prototype.slice.call(arguments).join(' '))
+    .split(/\s*\n\s*/)
+    .join('\n  ');
+  return new Error(message);
+}
+
+module.exports = getError;