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/escalade/sync/index.mjs

@@ -0,0 +1,18 @@
+import { dirname, resolve } from 'path';
+import { readdirSync, statSync } from 'fs';
+
+export default function (start, callback) {
+	let dir = resolve('.', start);
+	let tmp, stats = statSync(dir);
+
+	if (!stats.isDirectory()) {
+		dir = dirname(dir);
+	}
+
+	while (true) {
+		tmp = callback(dir, readdirSync(dir));
+		if (tmp) return resolve(dir, tmp);
+		dir = dirname(tmp = dir);
+		if (tmp === dir) break;
+	}
+}