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/wifi-off.js

@@ -0,0 +1,21 @@
+/**
+ * @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 WifiOff = createLucideIcon("WifiOff", [
+  ["line", { x1: "2", x2: "22", y1: "2", y2: "22", key: "a6p6uj" }],
+  ["path", { d: "M8.5 16.5a5 5 0 0 1 7 0", key: "sej527" }],
+  ["path", { d: "M2 8.82a15 15 0 0 1 4.17-2.65", key: "11utq1" }],
+  ["path", { d: "M10.66 5c4.01-.36 8.14.9 11.34 3.76", key: "hxefdu" }],
+  ["path", { d: "M16.85 11.25a10 10 0 0 1 2.22 1.68", key: "q734kn" }],
+  ["path", { d: "M5 13a10 10 0 0 1 5.24-2.76", key: "piq4yl" }],
+  ["line", { x1: "12", x2: "12.01", y1: "20", y2: "20", key: "of4bc4" }]
+]);
+
+export { WifiOff as default };
+//# sourceMappingURL=wifi-off.js.map