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/recharts/es6/util/Global.js

@@ -0,0 +1,21 @@
+var parseIsSsrByDefault = function parseIsSsrByDefault() {
+  return !(typeof window !== 'undefined' && window.document && window.document.createElement && window.setTimeout);
+};
+export var Global = {
+  isSsr: parseIsSsrByDefault(),
+  get: function get(key) {
+    return Global[key];
+  },
+  set: function set(key, value) {
+    if (typeof key === 'string') {
+      Global[key] = value;
+    } else {
+      var keys = Object.keys(key);
+      if (keys && keys.length) {
+        keys.forEach(function (k) {
+          Global[k] = key[k];
+        });
+      }
+    }
+  }
+};