Add live_action guard to handle_info({:update, record}) in both
CollectionLive.Show and WishlistLive.Show. When the user is editing,
background worker updates are skipped and a warning toast is shown
instead of overwriting the socket. Normal show-mode updates and
mismatched-ID no-ops are unchanged.
6 tests added covering all three code paths.
Claudio Ortolina
e204e555bd