Shared RealtimeProvider opens ONE dashboard-wide IIOS message socket reused by
the messenger tab and the new NotificationCenter. CrmMessagingAdapter gains
setFocus (drives presence/push suppression) and subscribeActivity (joins all
of the caller's threads, fans out incoming messages). NotificationCenter shows
a clickable toast on new messages when you're not on the messenger tab and
deep-links to the conversation. Pulls @insignia/iios-messaging-ui@0.1.7.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>