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/tractor.js

@@ -0,0 +1,23 @@
+/**
+ * @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 Tractor = createLucideIcon("Tractor", [
+  ["path", { d: "M3 4h9l1 7", key: "1ftpo8" }],
+  ["path", { d: "M4 11V4", key: "9ft8pt" }],
+  ["path", { d: "M8 10V4", key: "1y5f7n" }],
+  ["path", { d: "M18 5c-.6 0-1 .4-1 1v5.6", key: "10zbvr" }],
+  ["path", { d: "m10 11 11 .9c.6 0 .9.5.8 1.1l-.8 5h-1", key: "2w242w" }],
+  ["circle", { cx: "7", cy: "15", r: ".5", key: "fbsjqy" }],
+  ["circle", { cx: "7", cy: "15", r: "5", key: "ddtuc" }],
+  ["path", { d: "M16 18h-5", key: "bq60fd" }],
+  ["circle", { cx: "18", cy: "18", r: "2", key: "1emm8v" }]
+]);
+
+export { Tractor as default };
+//# sourceMappingURL=tractor.js.map