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/flashlight-off.js

@@ -0,0 +1,18 @@
+/**
+ * @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 FlashlightOff = createLucideIcon("FlashlightOff", [
+  ["path", { d: "M16 16v4a2 2 0 0 1-2 2h-4a2 2 0 0 1-2-2V10c0-2-2-2-2-4", key: "1r120k" }],
+  ["path", { d: "M7 2h11v4c0 2-2 2-2 4v1", key: "dz1920" }],
+  ["line", { x1: "11", x2: "18", y1: "6", y2: "6", key: "bi1vpe" }],
+  ["line", { x1: "2", x2: "22", y1: "2", y2: "22", key: "a6p6uj" }]
+]);
+
+export { FlashlightOff as default };
+//# sourceMappingURL=flashlight-off.js.map