A payment that settled while the app was backgrounded stayed invisible
until the user pressed Refresh by hand.
`onPause` closes the socket to save battery, and the LNbits websocket
only pushes on live events — it replays nothing on reconnect. `onResume`
reconnected the socket and stopped there, so the notification for
anything that settled in between reached no one. Balance and the
transaction list both sat at their pre-pause values.
`onResume` now pairs reconnection with an explicit refetch of both: the
balance via PaymentService and the rows via WalletService. Neither
implies the other, so both are needed. `allSettled` keeps a failure in
one from leaving the other un-refreshed.
The balance fetch is extracted from the polling fallback rather than
duplicated, so the two paths cannot drift.
Verified against the live LNbits with a real internal payment:
socket closed (backgrounded)
paid a 33-sat invoice, waited 5s so the notification task fired
reconnected -> nothing arrived in 8s; the 33 sats were invisible
REST refetch -> 283633 sat, a 33 sat delta the UI had missed
A first attempt reconnected immediately and did see a message. That was
a test artifact, not a replay: LNbits dispatches the notification from
an async task, which found the new socket. Hence the deliberate delay
above, which is what a backgrounded app actually looks like.
