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/math-intrinsics/isFinite.js

@@ -0,0 +1,12 @@
+'use strict';
+
+var $isNaN = require('./isNaN');
+
+/** @type {import('./isFinite')} */
+module.exports = function isFinite(x) {
+	return (typeof x === 'number' || typeof x === 'bigint')
+        && !$isNaN(x)
+        && x !== Infinity
+        && x !== -Infinity;
+};
+