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/import.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 Import = createLucideIcon("Import", [
+  ["path", { d: "M12 3v12", key: "1x0j5s" }],
+  ["path", { d: "m8 11 4 4 4-4", key: "1dohi6" }],
+  [
+    "path",
+    {
+      d: "M8 5H4a2 2 0 0 0-2 2v10a2 2 0 0 0 2 2h16a2 2 0 0 0 2-2V7a2 2 0 0 0-2-2h-4",
+      key: "1ywtjm"
+    }
+  ]
+]);
+
+export { Import as default };
+//# sourceMappingURL=import.js.map