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/follow-redirects/debug.js

@@ -0,0 +1,15 @@
+var debug;
+
+module.exports = function () {
+  if (!debug) {
+    try {
+      /* eslint global-require: off */
+      debug = require("debug")("follow-redirects");
+    }
+    catch (error) { /* */ }
+    if (typeof debug !== "function") {
+      debug = function () { /* */ };
+    }
+  }
+  debug.apply(null, arguments);
+};