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/eslint-plugin-jsx-a11y/lib/util/getExplicitRole.js

@@ -0,0 +1,27 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports["default"] = getExplicitRole;
+var _ariaQuery = require("aria-query");
+var _jsxAstUtils = require("jsx-ast-utils");
+/**
+ * Returns an element's computed role, which is
+ *
+ *  1. The valid value of its explicit role attribute; or
+ *  2. The implicit value of its tag.
+ */
+function getExplicitRole(tag, attributes) {
+  var explicitRole = function toLowerCase(role) {
+    if (typeof role === 'string') {
+      return role.toLowerCase();
+    }
+    return null;
+  }((0, _jsxAstUtils.getLiteralPropValue)((0, _jsxAstUtils.getProp)(attributes, 'role')));
+  if (_ariaQuery.roles.has(explicitRole)) {
+    return explicitRole;
+  }
+  return null;
+}
+module.exports = exports.default;