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/object-is/test/shimmed.js

@@ -0,0 +1,28 @@
+'use strict';
+
+require('../auto');
+
+var runTests = require('./tests');
+
+var test = require('tape');
+var defineProperties = require('define-properties');
+var callBind = require('call-bind');
+var isEnumerable = Object.prototype.propertyIsEnumerable;
+var functionsHaveNames = require('functions-have-names')();
+
+test('shimmed', function (t) {
+	t.equal(Object.is.length, 2, 'Object.is has a length of 2');
+	t.test('Function name', { skip: !functionsHaveNames }, function (st) {
+		st.equal(Object.is.name, 'is', 'Object.is has name "is"');
+		st.end();
+	});
+
+	t.test('enumerability', { skip: !defineProperties.supportsDescriptors }, function (et) {
+		et.equal(false, isEnumerable.call(Object, 'is'), 'Object.is is not enumerable');
+		et.end();
+	});
+
+	runTests(callBind(Object.is, Object), t);
+
+	t.end();
+});