Dashboard hangs on the loading screen after resuming a PWA

### Current Behavior

Occasionally, when returning to an installed PWA, the dashboard hangs on the loading screen forever. The Node-RED icon shows for a couple of seconds, then it switches to the loading screen with the cycling dots and just sits there indefinitely. It does not recover on its own; a swipe-down force-refresh fixes it.

It is intermittent (roughly zero to a couple of times a day) and more likely to surface under heavy reconnect churn, e.g. a short auth-token expiry. It appears to be pre-existing, reported by @colinl.

### Expected Behavior

On returning to the PWA the dashboard should finish loading, or recover on its own, rather than hang on the loading screen until a manual refresh.

### Steps To Reproduce

Intermittent, so not reliably reproducible by hand:

1. Install the dashboard as a PWA.
2. Use it normally, ideally behind an auth proxy with a short session/token expiry to increase reconnect churn.
3. Background the app, then return to it.
4. Occasionally it reloads and hangs on the loading screen with the cycling dots.

### Environment

- Dashboard version: 1.31.0
- Node-RED version: 5.0.0
- Node.js version: 24
- npm version: 1.31.0
- Platform/OS: Android (installed PWA)
- Browser: Chrome

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

I have provided an initial effort estimate