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/file-cog.js

@@ -0,0 +1,28 @@
+/**
+ * @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 FileCog = createLucideIcon("FileCog", [
+  ["circle", { cx: "6", cy: "13", r: "3", key: "1z65bp" }],
+  ["path", { d: "m9.7 14.4-.9-.3", key: "o1luaq" }],
+  ["path", { d: "m3.2 11.9-.9-.3", key: "qm3zk5" }],
+  ["path", { d: "m4.6 16.7.3-.9", key: "1o0ect" }],
+  ["path", { d: "m7.6 16.7-.4-1", key: "1ym8d1" }],
+  ["path", { d: "m4.8 10.3-.4-1", key: "18q26g" }],
+  ["path", { d: "m2.3 14.6 1-.4", key: "121m88" }],
+  ["path", { d: "m8.7 11.8 1-.4", key: "9meqp2" }],
+  ["path", { d: "m7.4 9.3-.3.9", key: "136qqn" }],
+  ["path", { d: "M14 2v6h6", key: "1kof46" }],
+  [
+    "path",
+    { d: "M4 5.5V4a2 2 0 0 1 2-2h8.5L20 7.5V20a2 2 0 0 1-2 2H6a2 2 0 0 1-2-1.5", key: "xwe04" }
+  ]
+]);
+
+export { FileCog as default };
+//# sourceMappingURL=file-cog.js.map