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/save.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 Save = createLucideIcon("Save", [
+  ["path", { d: "M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z", key: "1owoqh" }],
+  ["polyline", { points: "17 21 17 13 7 13 7 21", key: "1md35c" }],
+  ["polyline", { points: "7 3 7 8 15 8", key: "8nz8an" }]
+]);
+
+export { Save as default };
+//# sourceMappingURL=save.js.map