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/es-define-property/index.js

@@ -0,0 +1,14 @@
+'use strict';
+
+/** @type {import('.')} */
+var $defineProperty = Object.defineProperty || false;
+if ($defineProperty) {
+	try {
+		$defineProperty({}, 'a', { value: 1 });
+	} catch (e) {
+		// IE 8 has a broken defineProperty
+		$defineProperty = false;
+	}
+}
+
+module.exports = $defineProperty;