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-react/lib/util/report.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const getMessageData = require('./message');
+
+module.exports = function report(context, message, messageId, data) {
+  context.report(
+    Object.assign(
+      getMessageData(messageId, message),
+      data
+    )
+  );
+};