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/lodash/math.js

@@ -0,0 +1,17 @@
+module.exports = {
+  'add': require('./add'),
+  'ceil': require('./ceil'),
+  'divide': require('./divide'),
+  'floor': require('./floor'),
+  'max': require('./max'),
+  'maxBy': require('./maxBy'),
+  'mean': require('./mean'),
+  'meanBy': require('./meanBy'),
+  'min': require('./min'),
+  'minBy': require('./minBy'),
+  'multiply': require('./multiply'),
+  'round': require('./round'),
+  'subtract': require('./subtract'),
+  'sum': require('./sum'),
+  'sumBy': require('./sumBy')
+};