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/providers/async.d.ts

@@ -0,0 +1,12 @@
+import AsyncReader from '../readers/async';
+import type Settings from '../settings';
+import type { Entry, Errno } from '../types';
+export declare type AsyncCallback = (error: Errno, entries: Entry[]) => void;
+export default class AsyncProvider {
+    private readonly _root;
+    private readonly _settings;
+    protected readonly _reader: AsyncReader;
+    private readonly _storage;
+    constructor(_root: string, _settings: Settings);
+    read(callback: AsyncCallback): void;
+}