Subscription payment warning is hidden by the environment banner

### Summary

When an environment has a custom banner configured and the organisation has a payment problem, the red "problem with your paid subscription" warning does not stay on screen. It flashes briefly on load and is then replaced by the environment banner. A payment warning ends up hidden on the pages people use most (Features and other environment views). It stays visible only on pages like Segments that are not tied to an environment.

### Steps to reproduce

1. Put an organisation into a failed payment state so the subscription warning would show
2. Turn on the Environment Banner for an environment in Environment Settings.
3. Open an environment page such as Features for that environment.
4. The red subscription warning flashes on load, then the environment banner replaces it.
5. Switch to Segments. The subscription warning shows and stays.

### Expected

The subscription payment warning stays visible whenever the organisation has a payment problem, whether or not an environment banner is configured.

### Actual

A configured environment banner hides the subscription warning on every environment page.

### Possible cause (to validate)

The environment banner and the subscription warning look like they are shown one instead of the other rather than together, so a configured environment banner seems to take over and suppress the subscription warning. The brief flash on load points at a timing issue where the warning renders before the environment banner data arrives and is then replaced. This also appears to affect the usage limit warning, not just the payment warning, so any critical account notice may be hidden while an environment banner is set.

### Preconditions

The environment has a custom banner configured AND the organisation is in a failed payment

Reproduce the issue from Environment Settings by opening an environment's Features page, then compare it with Segments where the subscription warning remains visible. Trace how the environment banner and subscription or usage-limit warnings are selected after loading; done means critical account warnings remain visible alongside the environment banner on environment pages.

Written by the indexing model from the issue text.