Store the setting in the NetworkTCPUnackedDataTimeout preference next to
the other keep-alive values, so it survives restart and is kept when other
screens resend the network config.
Represent off as null everywhere, so an unchanged settings screen compares
equal to the saved config and to the defaults, and the config sent with the
setting off is the same as before.
The desktop app polled full clipboard contents every second on the AWT
event thread to update ChatModel.clipboardHasText. On X11, each read
blocks up to sun.awt.datatransfer.timeout (10s) when the selection owner
does not respond (e.g. after KeePassXC's clipboard auto-clear), making
every click/scroll wait ~9s. clipboardHasText has had no readers since
its only consumer was removed in #4398, so the whole mechanism (desktop
poll, Android clip listener, onResume refresh, expect/actual, state
field) is deleted. See plans/2026-07-11-fix-desktop-clipboard-freeze.md.
Narasimha-sc