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/clipboard-edit.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 ClipboardEdit = createLucideIcon("ClipboardEdit", [
+  ["rect", { width: "8", height: "4", x: "8", y: "2", rx: "1", ry: "1", key: "tgr4d6" }],
+  [
+    "path",
+    { d: "M10.42 12.61a2.1 2.1 0 1 1 2.97 2.97L7.95 21 4 22l.99-3.95 5.43-5.44Z", key: "1rgxu8" }
+  ],
+  ["path", { d: "M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2h-5.5", key: "cereej" }],
+  ["path", { d: "M4 13.5V6a2 2 0 0 1 2-2h2", key: "5ua5vh" }]
+]);
+
+export { ClipboardEdit as default };
+//# sourceMappingURL=clipboard-edit.js.map