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/@nodelib/fs.walk/out/readers/sync.d.ts

@@ -0,0 +1,15 @@
+import * as fsScandir from '@nodelib/fs.scandir';
+import type { Entry } from '../types';
+import Reader from './reader';
+export default class SyncReader extends Reader {
+    protected readonly _scandir: typeof fsScandir.scandirSync;
+    private readonly _storage;
+    private readonly _queue;
+    read(): Entry[];
+    private _pushToQueue;
+    private _handleQueue;
+    private _handleDirectory;
+    private _handleError;
+    private _handleEntry;
+    private _pushToStorage;
+}