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/_isIterateeCall.js

@@ -0,0 +1,30 @@
+var eq = require('./eq'),
+    isArrayLike = require('./isArrayLike'),
+    isIndex = require('./_isIndex'),
+    isObject = require('./isObject');
+
+/**
+ * Checks if the given arguments are from an iteratee call.
+ *
+ * @private
+ * @param {*} value The potential iteratee value argument.
+ * @param {*} index The potential iteratee index or key argument.
+ * @param {*} object The potential iteratee object argument.
+ * @returns {boolean} Returns `true` if the arguments are from an iteratee call,
+ *  else `false`.
+ */
+function isIterateeCall(value, index, object) {
+  if (!isObject(object)) {
+    return false;
+  }
+  var type = typeof index;
+  if (type == 'number'
+        ? (isArrayLike(object) && isIndex(index, object.length))
+        : (type == 'string' && index in object)
+      ) {
+    return eq(object[index], value);
+  }
+  return false;
+}
+
+module.exports = isIterateeCall;