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/2023/ToInt8.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var modulo = require('./modulo');
+var ToNumber = require('./ToNumber');
+var truncate = require('./truncate');
+
+var isFinite = require('math-intrinsics/isFinite');
+
+// https://262.ecma-international.org/14.0/#sec-toint8
+
+module.exports = function ToInt8(argument) {
+	var number = ToNumber(argument);
+	if (!isFinite(number) || number === 0) {
+		return 0;
+	}
+	var int = truncate(number);
+	var int8bit = modulo(int, 0x100);
+	return int8bit >= 0x80 ? int8bit - 0x100 : int8bit;
+};