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/recharts/es6/chart/FunnelChart.js

@@ -0,0 +1,15 @@
+/**
+ * @fileOverview Funnel Chart
+ */
+import { generateCategoricalChart } from './generateCategoricalChart';
+import { Funnel } from '../numberAxis/Funnel';
+export var FunnelChart = generateCategoricalChart({
+  chartName: 'FunnelChart',
+  GraphicalChild: Funnel,
+  validateTooltipEventTypes: ['item'],
+  defaultTooltipEventType: 'item',
+  axisComponents: [],
+  defaultProps: {
+    layout: 'centric'
+  }
+});