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-wsl/index.js

@@ -0,0 +1,31 @@
+'use strict';
+const os = require('os');
+const fs = require('fs');
+const isDocker = require('is-docker');
+
+const isWsl = () => {
+	if (process.platform !== 'linux') {
+		return false;
+	}
+
+	if (os.release().toLowerCase().includes('microsoft')) {
+		if (isDocker()) {
+			return false;
+		}
+
+		return true;
+	}
+
+	try {
+		return fs.readFileSync('/proc/version', 'utf8').toLowerCase().includes('microsoft') ?
+			!isDocker() : false;
+	} catch (_) {
+		return false;
+	}
+};
+
+if (process.env.__IS_WSL_TEST__) {
+	module.exports = isWsl;
+} else {
+	module.exports = isWsl();
+}