Frequent "site has been updated in the background" notifications for PWA

[taoeffect]

Problem

On Android with a Brave PWA, I am getting these notifications entirely too frequently (many times an hour):

What's more, is that these notifications often come in pairs for both the live site and testing, at the same time. This indicates that something else is going on than contract activity, especially the contracts in both don't have much activity.

Solution

• First find out why this is happening, perhaps by using more verbose logging with console.info (will the logs be captured if the PWA isn't open..?)
• Then fix it so that they appear only to the minimum extent necessary.

EDIT: @corrideat has a theory that it may be that we're broadcasting KV updates over push. If so, we should disable this, as I see no reason to do so. Disabling will cause this message to appear less frequently. When we come back online (because the user opens the app) we should immediately query the KV stores for updates.

These KV updates are being broadcast multiple times a minute on the debug server, which almost nobody is using, so these definitely shouldn't be sent over push anyway: