- Drops the web-local ApprovalRequest interface in favor of the
canonical shared type (Task 2 already established this; Task 10
reconciles the consumer side).
- Adds five new federation methods wrapping the REST endpoints
added in Tasks 8 and 9: peeringSubscriptions (GET), cancelPeering
Subscription (DELETE), peeringNotifications (GET +/- unreadOnly
filter), markPeeringNotificationRead (POST :id/read), markAll
PeeringNotificationsRead (POST read-all).