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/_createPadding.js

@@ -0,0 +1,33 @@
+var baseRepeat = require('./_baseRepeat'),
+    baseToString = require('./_baseToString'),
+    castSlice = require('./_castSlice'),
+    hasUnicode = require('./_hasUnicode'),
+    stringSize = require('./_stringSize'),
+    stringToArray = require('./_stringToArray');
+
+/* Built-in method references for those with the same name as other `lodash` methods. */
+var nativeCeil = Math.ceil;
+
+/**
+ * Creates the padding for `string` based on `length`. The `chars` string
+ * is truncated if the number of characters exceeds `length`.
+ *
+ * @private
+ * @param {number} length The padding length.
+ * @param {string} [chars=' '] The string used as padding.
+ * @returns {string} Returns the padding for `string`.
+ */
+function createPadding(length, chars) {
+  chars = chars === undefined ? ' ' : baseToString(chars);
+
+  var charsLength = chars.length;
+  if (charsLength < 2) {
+    return charsLength ? baseRepeat(chars, length) : chars;
+  }
+  var result = baseRepeat(chars, nativeCeil(length / stringSize(chars)));
+  return hasUnicode(chars)
+    ? castSlice(stringToArray(result), 0, length).join('')
+    : result.slice(0, length);
+}
+
+module.exports = createPadding;