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/underscore/modules/toArray.js

@@ -0,0 +1,20 @@
+import isArray from './isArray.js';
+import { slice } from './_setup.js';
+import isString from './isString.js';
+import isArrayLike from './_isArrayLike.js';
+import map from './map.js';
+import identity from './identity.js';
+import values from './values.js';
+
+// Safely create a real, live array from anything iterable.
+var reStrSymbol = /[^\ud800-\udfff]|[\ud800-\udbff][\udc00-\udfff]|[\ud800-\udfff]/g;
+export default function toArray(obj) {
+  if (!obj) return [];
+  if (isArray(obj)) return slice.call(obj);
+  if (isString(obj)) {
+    // Keep surrogate pair characters together.
+    return obj.match(reStrSymbol);
+  }
+  if (isArrayLike(obj)) return map(obj, identity);
+  return values(obj);
+}