Every code location that sets federation_peers.status='active'
now invokes onPeerActivated(peerId, reason). HTTP handler sites
use fire-and-forget (.catch(log)) so the response isn't blocked
by sync-pull pagination. The worker-internal health-check site
awaits the handler since the tick is already async.
Sites: /peer/initiate, /peer/accept (4 branches), /approval-
requests/:id/approve, health check recovery, ensurePeered/
performHandshake.