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/es-abstract/2025/SetDataIndex.js

@@ -0,0 +1,32 @@
+'use strict';
+
+var $TypeError = require('es-errors/type');
+
+var CanonicalizeKeyedCollectionKey = require('./CanonicalizeKeyedCollectionKey');
+var SameValue = require('./SameValue');
+
+var isArray = require('../helpers/IsArray');
+
+// https://262.ecma-international.org/16.0/#sec-setdataindex
+
+module.exports = function SetDataIndex(setData, value) {
+	if (!isArray(setData) && setData !== 'EMPTY') {
+		throw new $TypeError('Assertion failed: `setData` must be a List or ~EMPTY~');
+	}
+
+	var canonValue = CanonicalizeKeyedCollectionKey(value); // step 1
+
+	var size = setData.length; // step 2
+
+	var index = 0; // step 3
+
+	while (index < size) { // step 4
+		var e = setData[index]; // step 4.a
+		if (/* e !== ~EMPTY~ && */ SameValue(e, canonValue)) { // step 4.b
+			return index; // step 4.b.i
+		}
+		index += 1; // step 4.c
+	}
+
+	return 'NOT-FOUND'; // step 5
+};