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/brain-cog.js

@@ -0,0 +1,30 @@
+/**
+ * @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 BrainCog = createLucideIcon("BrainCog", [
+  ["circle", { cx: "12", cy: "12", r: "3", key: "1v7zrd" }],
+  [
+    "path",
+    {
+      d: "M12 4.5a2.5 2.5 0 0 0-4.96-.46 2.5 2.5 0 0 0-1.98 3 2.5 2.5 0 0 0-1.32 4.24 3 3 0 0 0 .34 5.58 2.5 2.5 0 0 0 2.96 3.08A2.5 2.5 0 0 0 12 19.5a2.5 2.5 0 0 0 4.96.44 2.5 2.5 0 0 0 2.96-3.08 3 3 0 0 0 .34-5.58 2.5 2.5 0 0 0-1.32-4.24 2.5 2.5 0 0 0-1.98-3A2.5 2.5 0 0 0 12 4.5",
+      key: "1f4le0"
+    }
+  ],
+  ["path", { d: "m15.7 10.4-.9.4", key: "ayzo6p" }],
+  ["path", { d: "m9.2 13.2-.9.4", key: "1uzb3g" }],
+  ["path", { d: "m13.6 15.7-.4-.9", key: "11ifqf" }],
+  ["path", { d: "m10.8 9.2-.4-.9", key: "1pmk2v" }],
+  ["path", { d: "m15.7 13.5-.9-.4", key: "7ng02m" }],
+  ["path", { d: "m9.2 10.9-.9-.4", key: "1x66zd" }],
+  ["path", { d: "m10.5 15.7.4-.9", key: "3js94g" }],
+  ["path", { d: "m13.1 9.2.4-.9", key: "18n7mc" }]
+]);
+
+export { BrainCog as default };
+//# sourceMappingURL=brain-cog.js.map