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/case-upper.js

@@ -0,0 +1,17 @@
+/**
+ * @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 CaseUpper = createLucideIcon("CaseUpper", [
+  ["path", { d: "m3 15 4-8 4 8", key: "1vwr6u" }],
+  ["path", { d: "M4 13h6", key: "1r9ots" }],
+  ["path", { d: "M15 11h4.5a2 2 0 0 1 0 4H15V7h4a2 2 0 0 1 0 4", key: "1sqfas" }]
+]);
+
+export { CaseUpper as default };
+//# sourceMappingURL=case-upper.js.map