Empty "Dashboard 2.0" sidebar when widgets exist in locked and unlocked flows

### Current Behavior

For more than 1 month, the sidebar to organize and move dasboard items is blank.

### Expected Behavior

I am used to see an interface by which to view of your pages, themes, groups and widgets.

### Steps To Reproduce

_No response_

### Environment

- Dashboard version: 1.30.2
- Node-RED version: 4.1.1
- Node.js version:
- npm version:
- Platform/OS: iOS and Windows
- Browser: Chrome, Firefox and Edge

### Have you provided an initial effort estimate for this issue?

I am not a FlowFuse team member

Start by reproducing the empty Dashboard 2.0 sidebar on the listed browsers and platforms, checking both locked and unlocked flows. Trace the sidebar entry point that should display pages, themes, groups, and widgets. Done means those items are visible and can be organized or moved as expected.

Written by the indexing model from the issue text.