A busy install no longer breaks live views

When a page is showing live data and one update goes missing on the way to it, the page asks the server to send the whole picture again. If those requests are asked for repeatedly and nothing ever comes back, the page gives up and says so, which is what lets it reconnect instead of sitting on a spinner forever.

The check for "nothing ever comes back" was reading the wrong signal. The server acknowledged each request the instant it arrived — before it had actually produced the fresh copy — so a page that asked while the server was busy was told "acknowledged" three times in a few milliseconds and concluded that its answers were being lost. They were not: they were queued behind the very work that made the server busy.

During a large import or package install that is exactly what happens, so a perfectly healthy view was being cut off mid-install and had to be re-established. The server now acknowledges a request only once it has sent the answer, so "acknowledged with nothing behind it" means what it says. A view whose answer is merely slow now waits and catches up; a view whose answers really are being lost still gives up and reconnects, exactly as before.