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/folder-edit.js

@@ -0,0 +1,22 @@
+/**
+ * @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 FolderEdit = createLucideIcon("FolderEdit", [
+  ["path", { d: "M8.4 10.6a2.1 2.1 0 1 1 2.99 2.98L6 19l-4 1 1-3.9Z", key: "10ocjb" }],
+  [
+    "path",
+    {
+      d: "M2 11.5V5a2 2 0 0 1 2-2h3.9a2 2 0 0 1 1.69.9l.81 1.2a2 2 0 0 0 1.67.9H20a2 2 0 0 1 2 2v10a2 2 0 0 1-2 2h-9.5",
+      key: "1h3cz8"
+    }
+  ]
+]);
+
+export { FolderEdit as default };
+//# sourceMappingURL=folder-edit.js.map