Saved users are not being listed on the user selection screen

### Bug description

Accessed Cockpit via Electron, created a user and switched back to Cockpit web.
In both platforms the user selection dialog wasn't called, but the user creation dialog instead.

Also noticed that the `bag of holdings` on the vehicle was an empty object {}

Cockpit version: 1.17.0-beta.3
BlueOS version 1.5.0-beta.15

After that, tested on BlueOS 1.4 and on Cockpit 1.16.0 and had the same results. This may indicate it's a local setup problem. Still checking on that.

### Steps to reproduce

* Open Cockpit web and BlueOS;
* Check BlueOS bag of holdings contents;
* Save a new Cockpit user;
* Check bag of holdings again;
* Run Cockpit on Electron and try to access the user you just created

### Primary pain point(s)

_No response_

### Additional context

_No response_

### Prerequisites

- [x] I have checked to make sure that a similar request has not already been filed or fixed.

No source file, test, or entry point is named. Start by reproducing the listed web and Electron steps while checking the BlueOS bag of holdings, then determine whether the missing saved-user list and empty holdings object share a cause; done means saved users appear and can be selected on both platforms.

Written by the indexing model from the issue text.