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/@testing-library/user-event/dist/keyboard/specialCharMap.js

@@ -0,0 +1,30 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.specialCharMap = void 0;
+
+/**
+ * @deprecated This list of strings with special meaning is no longer necessary
+ * as we've introduced a standardized way to describe any keystroke for `userEvent`.
+ * @see https://testing-library.com/docs/ecosystem-user-event#keyboardtext-options
+ */
+const specialCharMap = {
+  arrowLeft: '{arrowleft}',
+  arrowRight: '{arrowright}',
+  arrowDown: '{arrowdown}',
+  arrowUp: '{arrowup}',
+  enter: '{enter}',
+  escape: '{esc}',
+  delete: '{del}',
+  backspace: '{backspace}',
+  home: '{home}',
+  end: '{end}',
+  selectAll: '{selectall}',
+  space: '{space}',
+  whitespace: ' ',
+  pageUp: '{pageUp}',
+  pageDown: '{pageDown}'
+};
+exports.specialCharMap = specialCharMap;