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/separator-vertical.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 SeparatorVertical = createLucideIcon("SeparatorVertical", [
+  ["line", { x1: "12", x2: "12", y1: "3", y2: "21", key: "1efggb" }],
+  ["polyline", { points: "8 8 4 12 8 16", key: "bnfmv4" }],
+  ["polyline", { points: "16 16 20 12 16 8", key: "u90052" }]
+]);
+
+export { SeparatorVertical as default };
+//# sourceMappingURL=separator-vertical.js.map