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/shirt.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 Shirt = createLucideIcon("Shirt", [
+  [
+    "path",
+    {
+      d: "M20.38 3.46 16 2a4 4 0 0 1-8 0L3.62 3.46a2 2 0 0 0-1.34 2.23l.58 3.47a1 1 0 0 0 .99.84H6v10c0 1.1.9 2 2 2h8a2 2 0 0 0 2-2V10h2.15a1 1 0 0 0 .99-.84l.58-3.47a2 2 0 0 0-1.34-2.23z",
+      key: "1wgbhj"
+    }
+  ]
+]);
+
+export { Shirt as default };
+//# sourceMappingURL=shirt.js.map