feat(scm-messaging-integrations-ui): Hiding other rows on complete (#123006)

Keeping two paths means list exclusivity and footer visibility can
change independently. activeRow still means “busy”: hide siblings and
the footer. A saved destination only needs the list filter, so Continue
stays. One flag would force Continue to follow sibling-hiding, or pile
on exceptions.

<img width="1068" height="604" alt="Screenshot 2026-08-28 at 11 12
03 AM"
src="https://github.com/user-attachments/assets/12283805-c6f0-4a8e-99c2-c162e840ef44"
/>