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/LineChart.js

@@ -0,0 +1,20 @@
+/**
+ * @fileOverview Line Chart
+ */
+import { generateCategoricalChart } from './generateCategoricalChart';
+import { Line } from '../cartesian/Line';
+import { XAxis } from '../cartesian/XAxis';
+import { YAxis } from '../cartesian/YAxis';
+import { formatAxisMap } from '../util/CartesianUtils';
+export var LineChart = generateCategoricalChart({
+  chartName: 'LineChart',
+  GraphicalChild: Line,
+  axisComponents: [{
+    axisType: 'xAxis',
+    AxisComp: XAxis
+  }, {
+    axisType: 'yAxis',
+    AxisComp: YAxis
+  }],
+  formatAxisMap: formatAxisMap
+});