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/feather.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 Feather = createLucideIcon("Feather", [
+  ["path", { d: "M20.24 12.24a6 6 0 0 0-8.49-8.49L5 10.5V19h8.5z", key: "u4sw5n" }],
+  ["line", { x1: "16", x2: "2", y1: "8", y2: "22", key: "1c47m2" }],
+  ["line", { x1: "17.5", x2: "9", y1: "15", y2: "15", key: "2fj3pr" }]
+]);
+
+export { Feather as default };
+//# sourceMappingURL=feather.js.map