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/is-path-inside/index.js

@@ -0,0 +1,12 @@
+'use strict';
+const path = require('path');
+
+module.exports = (childPath, parentPath) => {
+	const relation = path.relative(parentPath, childPath);
+	return Boolean(
+		relation &&
+		relation !== '..' &&
+		!relation.startsWith(`..${path.sep}`) &&
+		relation !== path.resolve(childPath)
+	);
+};