feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/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;
+}