* feat: add notification suppression rules
* fix: restore label routing and routing test mocks for suppression
* fix: allow bell mute shortcuts for history-only notification categories
Suppression rule validation used the routable category whitelist, which rejected history-only categories such as update_started that appear in the bell during stack updates.
* feat: expand Mute Rules UX with compose-first entry points and activity badges
* fix: add missing NodeContext mocks for notification suppression tests
Anso