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/@babel/runtime/helpers/createSuper.js

@@ -0,0 +1,16 @@
+var getPrototypeOf = require("./getPrototypeOf.js");
+var isNativeReflectConstruct = require("./isNativeReflectConstruct.js");
+var possibleConstructorReturn = require("./possibleConstructorReturn.js");
+function _createSuper(t) {
+  var r = isNativeReflectConstruct();
+  return function () {
+    var e,
+      o = getPrototypeOf(t);
+    if (r) {
+      var s = getPrototypeOf(this).constructor;
+      e = Reflect.construct(o, arguments, s);
+    } else e = o.apply(this, arguments);
+    return possibleConstructorReturn(this, e);
+  };
+}
+module.exports = _createSuper, module.exports.__esModule = true, module.exports["default"] = module.exports;