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/index.js

@@ -0,0 +1,38 @@
+'use strict';
+
+var assign = require('./helpers/assign');
+
+var ES5 = require('./es5');
+var ES2015 = require('./es2015');
+var ES2016 = require('./es2016');
+var ES2017 = require('./es2017');
+var ES2018 = require('./es2018');
+var ES2019 = require('./es2019');
+var ES2020 = require('./es2020');
+var ES2021 = require('./es2021');
+var ES2022 = require('./es2022');
+var ES2023 = require('./es2023');
+var ES2024 = require('./es2024');
+var ES2025 = require('./es2025');
+
+var ES = {
+	ES5: ES5,
+	ES6: ES2015,
+	ES2015: ES2015,
+	ES7: ES2016,
+	ES2016: ES2016,
+	ES2017: ES2017,
+	ES2018: ES2018,
+	ES2019: ES2019,
+	ES2020: ES2020,
+	ES2021: ES2021,
+	ES2022: ES2022,
+	ES2023: ES2023,
+	ES2024: ES2024,
+	ES2025: ES2025
+};
+assign(ES, ES5);
+delete ES.CheckObjectCoercible; // renamed in ES6 to RequireObjectCoercible
+assign(ES, ES2015);
+
+module.exports = ES;