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/workbox-precaching/addPlugins.d.ts

@@ -0,0 +1,11 @@
+import { WorkboxPlugin } from 'workbox-core/types.js';
+import './_version.js';
+/**
+ * Adds plugins to the precaching strategy.
+ *
+ * @param {Array<Object>} plugins
+ *
+ * @memberof workbox-precaching
+ */
+declare function addPlugins(plugins: WorkboxPlugin[]): void;
+export { addPlugins };