Remote instances - consistent story from home page to remote instances list

This relates to Improve Remote Instance Status for long-gone / offline devices https://github.com/FlowFuse/flowfuse/issues/7790

## Details

As discussed in the eng meeting and [this slack thread](https://flowfuse.slack.com/archives/C032Q63FGG1/p1784731082399259) - we introduced a new `online`/`offline`/`never seen` status. This new status conflicts with the story told on the home page:

For example, you can show like 53 `running` devices, but when you view them on the list, they are all `offline`. This is confusing.

## Refinement needed

We need to refine this ticket and discuss what user story we want to tell, and what changes we need to make to tell a consistent user story across the application.