The scope predicate of the channel list background task was entirely commented
out, so it returned undefined: setBackgroundTask stopped after the first
interval and the list was loaded once, never refreshed while the page stayed
open. It now tests the route like the boards one does.
The three group lists polled at three different periods: forums every 5 s,
boards every 30 s, channels never. Each poll fetches the whole summaries list,
and on a phone it costs a fresh TCP handshake on a server that answers one
request at a time. All three now share the boards period, named per page.
Added Navbar for webui on phones
for Boards and Channels:
* Validate API responses before processing.
* Keep rendering/navigation functional if a response is incomplete.
* Log a clear warning instead of throwing an uncaught error.
* Use independent sorted arrays, avoiding mutation of the master list.
