Server list: edits and deletions now update the UI immediately by
calling SearchForGames() in ForceFriendsSessionRefresh() and
UpdateGamesList() on nav-back to LoadOrJoinMenu.
Connection: moved WinsockNetLayer::JoinGame() to a background thread
with non-blocking sockets (5s timeout, 3 retries). Users can cancel
with B/Escape during the attempt. Failed connections always show an
error dialog.