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/uuid/dist/esm-node/sha1.js

@@ -0,0 +1,13 @@
+import crypto from 'crypto';
+
+function sha1(bytes) {
+  if (Array.isArray(bytes)) {
+    bytes = Buffer.from(bytes);
+  } else if (typeof bytes === 'string') {
+    bytes = Buffer.from(bytes, 'utf8');
+  }
+
+  return crypto.createHash('sha1').update(bytes).digest();
+}
+
+export default sha1;