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/.jshintrc

@@ -0,0 +1,28 @@
+{
+  "bitwise": true,
+  "camelcase": true,
+  "curly": true,
+  "eqeqeq": true,
+  "forin": false,
+  "freeze": false,
+  "immed": true,
+  "indent": 2,
+  "latedef": "nofunc",
+  "newcap": true,
+  "noarg": true,
+  "noempty": true,
+  "nonbsp": true,
+  "nonew": true,
+  "plusplus": false,
+  "quotmark": "single",
+  "undef": true,
+  "unused": true,
+  "strict": true,
+  "maxparams": 20,
+  "maxdepth": 5,
+  "maxlen": 120,
+  "scripturl": true,
+  "node": true,
+  "esnext": true,
+  "jasmine": true
+}