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/lucide-react/dist/esm/icons/bar-chart.js

@@ -0,0 +1,17 @@
+/**
+ * @license lucide-react v0.303.0 - ISC
+ *
+ * This source code is licensed under the ISC license.
+ * See the LICENSE file in the root directory of this source tree.
+ */
+
+import createLucideIcon from '../createLucideIcon.js';
+
+const BarChart = createLucideIcon("BarChart", [
+  ["line", { x1: "12", x2: "12", y1: "20", y2: "10", key: "1vz5eb" }],
+  ["line", { x1: "18", x2: "18", y1: "20", y2: "4", key: "cun8e5" }],
+  ["line", { x1: "6", x2: "6", y1: "20", y2: "16", key: "hq0ia6" }]
+]);
+
+export { BarChart as default };
+//# sourceMappingURL=bar-chart.js.map