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/file-heart.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 FileHeart = createLucideIcon("FileHeart", [
+  ["path", { d: "M4 6V4a2 2 0 0 1 2-2h8.5L20 7.5V20a2 2 0 0 1-2 2H4", key: "dba9qu" }],
+  ["polyline", { points: "14 2 14 8 20 8", key: "1ew0cm" }],
+  [
+    "path",
+    {
+      d: "M10.29 10.7a2.43 2.43 0 0 0-2.66-.52c-.29.12-.56.3-.78.53l-.35.34-.35-.34a2.43 2.43 0 0 0-2.65-.53c-.3.12-.56.3-.79.53-.95.94-1 2.53.2 3.74L6.5 18l3.6-3.55c1.2-1.21 1.14-2.8.19-3.74Z",
+      key: "1c1fso"
+    }
+  ]
+]);
+
+export { FileHeart as default };
+//# sourceMappingURL=file-heart.js.map