Migrate granular anycast kernel lifecycle event consumers to the unified transition handler

Migrate the consumers that update kernel status on granular anycast lifecycle events to the single unified transition handler, then REMOVE the now-unused granular anycast lifecycle events and their emission (the emission was added alongside in BA-6851). Broadcast granular events are retained (UI/streaming).

Success Criteria:
- [ ] Status-updating consumers of granular anycast events replaced by the unified transition handler
- [ ] Unused granular anycast events and their emission removed (broadcast retained; no regression)
- [ ] pants test passes for affected packages

JIRA Issue: BA-6853

Start by locating the granular anycast lifecycle event definitions, their emitters, status-updating consumers, and the unified transition handler. Compare the affected paths, then run pants test for the affected packages; done means consumers use the unified handler, unused anycast events and emission are removed, broadcast events remain, and tests pass.

Written by the indexing model from the issue text.