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/es-get-iterator/test/node.mjs

@@ -0,0 +1,10 @@
+import getIterator from 'es-get-iterator';
+import Module from 'module';
+
+const require = Module.createRequire(import.meta.url);
+const id = require.resolve('../node');
+const mod = new Module(id);
+mod.exports = getIterator;
+require.cache[id] = mod;
+
+require('./');