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/message-square-reply.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 MessageSquareReply = createLucideIcon("MessageSquareReply", [
+  ["path", { d: "M21 15a2 2 0 0 1-2 2H7l-4 4V5a2 2 0 0 1 2-2h14a2 2 0 0 1 2 2z", key: "1lielz" }],
+  ["path", { d: "m10 7-3 3 3 3", key: "1eugdv" }],
+  ["path", { d: "M17 13v-1a2 2 0 0 0-2-2H7", key: "ernfh3" }]
+]);
+
+export { MessageSquareReply as default };
+//# sourceMappingURL=message-square-reply.js.map