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/@sinonjs/commons/lib/index.js

@@ -0,0 +1,14 @@
+"use strict";
+
+module.exports = {
+    global: require("./global"),
+    calledInOrder: require("./called-in-order"),
+    className: require("./class-name"),
+    deprecated: require("./deprecated"),
+    every: require("./every"),
+    functionName: require("./function-name"),
+    orderByFirstCall: require("./order-by-first-call"),
+    prototypes: require("./prototypes"),
+    typeOf: require("./type-of"),
+    valueToString: require("./value-to-string"),
+};