Site error display during deployment

[onewheelskyward]

The display when clicking links during deployments is sub-optimal, let's see about replacing this display with a note about waiting a few minutes and trying again, or something.

[nolessafool]

We should check what if any HTTP status the app throws in this situation. if it just never responds I guess we need a timer to notice and Do Something (though...what timer do we set? 10s could be a real wait if you have e.g. a long search query but 20s they've already walked away...)
...however, if they throw some error code maybe we could get some text thrown into the 4xx response?

Or, if we are struggling to get a working deploy while the app is down, or know it will take awhile for whatever reason, we could use the maintenance playbook: https://github.com/shift-org/shift-docs/blob/main/docs/MAINTENANCE.md