- Combobox gains `error` (said in the list, not "No matches") and a soft `disabled` (keeps the
focus, announced, opens and changes nothing).
- UserPicker passes both: the share dialog's recipient picker is off while a share is pending, and
the share and quota pickers say when the user list failed to load.
- ChannelPicker and the Plex playlist/collection pickers say a failed load too.
- The channel menu's Tags row says loading / failed instead of "no tags yet".