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/plug-zap.js

@@ -0,0 +1,22 @@
+/**
+ * @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 PlugZap = createLucideIcon("PlugZap", [
+  [
+    "path",
+    { d: "M6.3 20.3a2.4 2.4 0 0 0 3.4 0L12 18l-6-6-2.3 2.3a2.4 2.4 0 0 0 0 3.4Z", key: "goz73y" }
+  ],
+  ["path", { d: "m2 22 3-3", key: "19mgm9" }],
+  ["path", { d: "M7.5 13.5 10 11", key: "7xgeeb" }],
+  ["path", { d: "M10.5 16.5 13 14", key: "10btkg" }],
+  ["path", { d: "m18 3-4 4h6l-4 4", key: "16psg9" }]
+]);
+
+export { PlugZap as default };
+//# sourceMappingURL=plug-zap.js.map