Class ChannelInSessionDelivery

The in-session tier over the sessions' Push Notification (PN) channels (PUSH-PROPS-DESIGN section 9.1, ruled 2026-09-24 RR-14a; P4-10): deliver(DeliveryTarget, IPushNotification) triggers DELIVER on the target session's PushChannelProps with the notification object as the Web Push leg carries it, and answers DeliveryOutcome.DELIVERED_IN_SESSION. The client shows it on its Service Worker registration where it has one, so that it looks and reports like a device push and its click goes through the worker, and with the in-app toaster otherwise.

A target whose session is gone answers DeliveryOutcome.IN_APP_SESSION_USER_CLOSED_ALL_SESSIONS: the session was live when the plan was made and closed before dispatch, which is the code the engine's ruled fallback acts on (a device push under PREFER_IN_SESSION; under the other modes the devices were dispatched by the same send). A target whose session has no channel at all - which the enumerator never produces, since it lists only sessions with one - answers DeliveryOutcome.IN_APP_SESSION_USER_NOT_FOUND.

Runs on the engine's dispatch thread. Nothing here waits: the channel queues the event and the property chain posts the flush to the session's worker.