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/istanbul-reports/lib/html-spa/webpack.config.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const path = require('path');
+
+module.exports = {
+    entry: path.resolve(__dirname, 'src/index.js'),
+    output: {
+        path: path.resolve(__dirname, 'assets'),
+        filename: 'bundle.js'
+    },
+    module: {
+        rules: [
+            {
+                test: /\.js$/,
+                exclude: /node_modules/,
+                use: {
+                    loader: 'babel-loader'
+                }
+            }
+        ]
+    }
+};